One day this spring, on the condition that I not reveal any details of its location nor the stringent security measures in place to protect its contents, I entered a hidden vault at the Israel Museum and gazed upon the Aleppo Codex -- the oldest, most complete, most accurate text of the Hebrew Bible. The story of how it arrived here, in Jerusalem, is a tale of ancient fears and modern prejudices, one that touches on one of the rawest nerves in Israeli society: the clash of cultures between Jews from Arab countries and the European Jews, or Ashkenazim, who controlled the country during its formative years. And the story of how some 200 pages of the codex went missing -- and to this day remain the object of searches carried out around the globe by biblical scholars, private investigators, shadowy businessmen and the Mossad, Israel's intelligence agency -- is one of the great mysteries in Jewish history.As a small group of us stood in a circle inside the vault in which the codex now resides, Michael Maggen, the head of the museum's paper-conservation lab, donned a pair of gloves and carefully lifted one of its unbound pages, covered with three columns of beautiful calligraphy, for us to see. The pages were made from animal hides that were stretched and bleached and cut to make parchment; the scribe's ink was made of powdered tree galls mixed with iron sulfate and black soot. ''Considering the difficult conditions that the manuscript suffered over a great many years,'' James Snyder, the museum's director, said, ''it is in remarkably excellent condition.'' Snyder was happy to talk about how fortunate the museum was to be able to display the codex alongside the 2,000-year-old Dead Sea Scrolls and about the painstaking restoration that has taken place. But he refused to speculate on the sensitive question of where the missing pages, which constitute about 40 percent of the codex and whose value is estimated to be in the many millions of dollars, might be and how they might have disappeared.

To talk to the many individuals who are obsessed with finding the missing portions of the codex or solving the mystery of who stole them, or whose histories are somehow bound up with the story of the book, is to get a glimpse of the power it has held over people for more than a thousand years. In Aleppo, Syria, where the codex was safeguarded for six centuries, it was believed to possess magical properties. It was said that women who looked upon it would become pregnant, that those who held the keys to its safe were blessed, that anyone who stole or sold the codex was cursed and that a terrible plague would wipe out the Jewish community if it were removed from their synagogue. At the tops of some of the pages, the Aleppo elders inscribed a warning to would-be thieves: ''Sacred to Yahweh, not to be sold or defiled.'' And elsewhere: ''Cursed be he who steals it, and cursed be he who sells it.'' Among some parties, those fears persist even today.

For a thousand years after the Dead Sea Scrolls were written, the Jewish holy scriptures -- the five parts of the Torah and 19 other holy books -- were copied and passed down in the various Jewish communities from generation to generation. Some of these texts, according to Jewish faith, were handed down directly by God and included signs, messages and codes that pertained directly to the essence of existence. The multiplicity of manuscripts and the worry that any change or inaccurate transcription would lead to the loss of vital esoteric knowledge created the need for a single, authoritative text. And beyond its mystical significance, a unified text was also necessary to maintain Jewish unity after the destruction of the Second Temple in Jerusalem by the Roman Empire. As Adolfo Roitman, the head of the Shrine of the Book, where the Dead Sea Scrolls and parts of the codex are displayed, said: ''One can regard the thousand years between the scrolls and the codex, the millennium during which the standardization of the text was carried out, as a metaphor for the effort of the Jewish people to create national unity. One text, one people, even if it is scattered to the four ends of the earth.''

According to tradition, early in the sixth century, a group of sages led by the Ben-Asher family in Tiberias, on the Sea of Galilee, undertook the task of creating a formal and final text. The use of codex technology -- a method that made it possible to record information on both sides of a page, in book form, as a cheaper alternative to scrolls -- had already evolved in Rome. Around A.D. 930, the sages in Tiberias assembled all 24 holy books and completed the writing of the codex, the first definitive Tanakh, or Hebrew Bible. From Tiberias, the codex was taken to Jerusalem. But Crusaders laid waste to the city in 1099, slaughtering its inhabitants and taking the codex. The prosperous Jewish community of Fustat, near Cairo, paid a huge ransom for it. Later, in the 12th century, it served Maimonides, who referred to it as the most accurate holy text, as a reference for his major work, the Mishneh Torah. In the 14th century, the great-great-great-grandson of Maimonides migrated to Aleppo, bringing the codex with him. There it was kept, for the next 600 years, in a safe within a small crypt hewed in the rock beneath Aleppo's great synagogue.

The story of what happened next -- how the codex came to Israel and where the missing pages might have gone -- is a murky and often contradictory one, told by many self-serving or unreliable narrators. In his book, ''The Aleppo Codex: A True Story of Obsession, Faith and the Pursuit of an Ancient Bible,'' published in May by Algonquin Books, the Canadian-Israeli journalist Matti Friedman presents a compelling and thoroughly researched account of the story, which served as the catalyst for additional reporting here.

Before the establishment of the State of Israel in 1948, Jewish leaders were intent on discovering and laying claim to their heritage in the region. They took an intense interest in archaeology, embarking on quests to bring significant items of Judaica to Palestine. The Aleppo Codex was one of their top priorities, but numerous attempts to retrieve it were thwarted, which for many Jews hailing from Aleppo was further proof of the myths surrounding the book. At the head of these ill-fated efforts was a leader of the Zionist movement, Yitzhak Ben-Zvi, a prominent politician and a scholar of some renown, with a special interest in Jewish communities in Arab lands. (He was also among the first members of the armed nucleus of Jews in Palestine and was involved in the assassination of an ultra-Orthodox opponent of the Zionist mission.)

In 1935, Ben-Zvi traveled to Aleppo, where the elders of the Jewish community allowed him only a glimpse of the case in which the codex was kept. When he tried to convince them that the volume belonged in Jerusalem, they rejected his entreaties as the manipulations of an outsider intent on taking what was theirs to protect. Eight years later, in the midst of World War II, Ben-Zvi and other scholars tried again to win over the Aleppo community, fearing that the codex, contained as it was in an Arab state during wartime, was in danger. In 1943, they dispatched a Hebrew University lecturer named Yitzhak Shamosh, who was a native of Aleppo, to try to extricate the codex. Shamosh endangered his life by crossing the border into Syria, but once there, he, too, was rebuffed by the Aleppo leaders. Some of the younger members of the community, however, sharing Ben-Zvi's fear that the codex was in danger, offered to help Shamosh steal it from the elders.

This spring, I spoke with his brother Amnon, who met Shamosh immediately upon his return to Jerusalem. ''He was aware of the curses surrounding the book,'' Amnon recalled. '' 'Cursed be its seller, cursed be its defiler and cursed be the community of Aram Tzova [the biblical Hebrew name for Aleppo] if it were to depart from there.' All of that would have been on his conscience. Ben-Zvi and the other superiors from the university were pressing him to take that upon himself, that he should wreck the Aleppo community. He just couldn't do it.''

When Shamosh reported back to Ben-Zvi about his failure to retrieve the codex, Ben-Zvi responded, ''It's a pity we sent an honest man.''

Amnon said, ''I saw him when he came back from that meeting with his fallen face.''

Ben-Zvi's fears about the codex proved correct. On Nov. 30, 1947, the morning after the U.N. General Assembly voted in favor of the establishment of a Jewish state, a mob stormed the Jewish quarter of Aleppo, attacking the Jews and demolishing their businesses and setting fire to the synagogues. Professor Yom Tov Assis, an Aleppo native who today heads the Ben-Zvi Institute, formed in 1948 for the purpose of studying Jewish communities under Islam and in the Arab world, was 5 years old at the time. ''I saw the mob kicking one of the rabbis and setting fire to the Jewish club,'' he said. ''The demonstrations and the yelling and the rioting went on for many days.''

News that the codex had been destroyed spread quickly across the globe. Because the elders in Aleppo forbade photographing the manuscript, the invaluable information that it contained was thought to have been lost forever. In Jerusalem, Yitzhak Shamosh grieved inconsolably at having let his fear of the curse prevent him from recovering it.

A few days after the riots began, a small group of community leaders learned that the reports of the destruction of the codex were premature. There are at least 10 accounts of how it was saved, but the true heroes appear to be the synagogue's sexton, Asher Baghdadi, and his son, who returned to the ashes of the synagogue and gathered the scattered pages.

The Syrian government took an interest in the codex after an American antiquities merchant offered $20 million for it, and so the leaders of the Aleppo synagogue went to great lengths to persuade Syrian intelligence that the book had been burned. For 10 years, even after word got out that the codex had not been destroyed, they kept it hidden in secret locations and refused to contemplate moving it from Aleppo.

Yitzhak Ben-Zvi became Israel's second president in 1952. Shortly after, he obtained a rabbinical ruling from the chief rabbi of Israel effectively annulling all curses connected to the codex and intensifying pressure on the Aleppo Jews to send it to Jerusalem. By this time, many Aleppo Jews had immigrated to New York, and some had become very wealthy. Ben-Zvi asked them to help sway the rabbis who remained in Syria, and he appealed to the American Jewish Joint Distribution Committee (an organization whose financial aid was necessary for the survival of the remaining community in Aleppo), to cut the flow of funds if the codex was not transferred to Israel.

In 1957, two Aleppo rabbis, fearing their community was approaching its demise, decided to take advantage of a chance to smuggle the codex to Aleppo Jews now living in Israel. Murad Faham, an Aleppo Jewish merchant who had been expelled from Syria, was chosen for the mission. ''Just before I left,'' Faham, who died in 1982, would later relate, ''Rabbi Moshe Tawil said to me, 'I want to tell you something, but I fear for your well-being, because this thing is a danger to your life, and whoever is caught doing it will be executed by hanging.' '' Faham, who would take every opportunity later to trumpet his own courage, recounted that he told the rabbi: ''With the help of God, I will take it out. Don't worry about my life, because if the Creator of the Universe has decreed that the book be taken out by me, it will be a great miracle that the Creator of the Universe is performing for my sake.''

A man in charge of looking after the codex arrived at Faham's residence carrying a sack that contained the precious cargo. According to a report based on an investigation conducted later, Faham's wife ''was aware of the importance of the contents of the sack and of the risks involved, and without opening it, she wrapped it up in sheets of cheesecloth'' -- the family earned its living making cheese -- ''and blankets and hid it in a washing machine.''

According to the official story told by the Ben-Zvi Institute, the head rabbis of Aleppo employed Faham to deliver the codex to President Ben-Zvi, and through him to the institute. But a number of documents, examined by Matti Friedman and discussed in his book, reveal an entirely different story. The rabbis in Aleppo did not enlist Faham to deliver the codex to the president or his institute, but rather to the chief rabbi of the Aleppo Jews. What the rabbis never suspected was that Israeli agents from the Mossad and the Jewish Agency (which was in charge of the Jewish diaspora and of immigration to Israel) had been in touch with Faham and that he would receive special treatment upon immigration to Israel.

Officials from the Jewish Agency met Faham in Turkey and informed authorities in Jerusalem of all his movements. When Faham arrived safely at the port in Haifa, instead of handing the codex to a representative of the Aleppo community, he handed it to a member of the Jewish Agency's immigration department, who passed it on to President Ben-Zvi.

''The official version of the story, the one I knew at the outset, states that the Aleppo Codex was given willingly to the State of Israel,'' Friedman told me. ''But that never happened. It was taken. The state authorities believed they were representatives of the entire Jewish people and that they were thus the book's rightful owners, and also, perhaps, that they could care for it better. But those considerations don't change the mechanics of the true story -- government officials engineered a sophisticated, international maneuver in which the codex was seized from the Jews of Aleppo, and then arranged a remarkably successful cover-up of the fascinating and unpleasant details of the affair.''

In February 1958, leaders of the Aleppo Jews petitioned the rabbinical court to order Ben-Zvi to return the codex to them. During the course of the trial, the two Aleppo rabbis who gave the book to Faham testified angrily that they had instructed him to hand it to the chief rabbi of the community in Israel, not to anyone else. Faham claimed that they left it to him to decide what should be done with it. Ben-Zvi's counsel asked that the details of the trial be kept secret, which remained so for 50 years.

Ezra Kassin, the head of the organization of Aleppo Jews in Israel today, has investigated the story of the codex and the fate of its missing pages for many years. He and Friedman recently managed to obtain the secret trial transcripts. According to the lawyer for the plaintiffs, Faham's testimony was full of contradictions. On March 27, the counsel for the state reported to President Ben-Zvi that Faham's cross-examination ''reached very high tension; but Mr. Faham stuck to his story.'' During the trial, representatives of the Aleppo Jewish community accused Faham of accepting perks from the Israeli establishment and Ben-Zvi's associates in exchange for handing the codex over to them, a charge that Faham denied. This month, I had a long conversation with his son at a shopping mall near Tel Aviv. He claimed that, first, it was his father and not the synagogue's sexton who rescued the codex after the synagogue was attacked (in his story, Faham went into the flames to rescue the book); and second, that Faham smuggled it out of Syria because he believed that it belonged to the Jewish people and not to one community. Everything else, the son asserted, was a pack of lies. ''My father never gave the codex to the [Aleppo] rabbis in Israel because he feared they would sell it,'' he said. ''He never received any perks from anyone.''

The trial dealt not only with the question of ownership of the codex but also touched on a far more profound issue: who represented Jewry, now that the State of Israel had been founded? It also forced a direct confrontation between the Zionist establishment, mostly Eastern European and secular in its makeup, and the community of Jews from Arab lands, who did not want to give up their cultural treasures. The trial ended when a secret compromise was agreed upon: the codex would continue to be housed at the Ben-Zvi Institute, but representatives of the Aleppo Jews would serve in a council overseeing the manuscript, along with Ben-Zvi and Faham.

The conflict with Israel's Aleppo community, combined with financial troubles, led Faham to emigrate to New York. From there, he went to great efforts to get Ben-Zvi to acknowledge that he had risked his life to recover the codex. After Faham requested his name be added to the codex in tribute to his efforts, Ben-Zvi eventually replied in May 1960, ''I am prepared to add a note to the bound edition of the codex that will say that it was brought to Israel by you.'' Almost a year later, waiting to see his request fulfilled, Faham wrote again: ''Without a shadow of a doubt, matters of supreme importance have kept you too occupied to deal with my petty request. Nevertheless, I have written once more to remind you that the matter should not be doomed to the dust of forgetfulness, for it is more important to me than all the money in the world.''

Faham, who seemed to know a secret about the codex that the Israeli establishment was trying fervidly to conceal, was clearly not placated by Ben-Zvi's words. Shlomo Zalman Shragai, the head of the Jewish Agency (and whose colleague was the one who took the codex from Faham at the Haifa port), tried to calm him but to no avail. ''The man who delivered [the codex] and who is in the United States cannot control himself any longer,'' Shragai wrote in a 1964 letter copied to Zalman Shazar, who had succeeded Ben-Zvi as president of Israel after his death a year earlier. ''I am very apprehensive that the matter will become public and turn into worldwide scandal.''

What did Faham know that would cause such a worldwide scandal? Most likely it was that the codex had arrived in Israel nearly whole. Yet only after its arrival did nearly 200 pages disappear. And perhaps it was this secret that led the codex, the most important Jewish book in existence, to not be restored and put on careful display but instead be stored in an iron case in the offices of the Ben-Zvi Institute at Hebrew University.

The man who fought most forcefully on behalf of the neglected codex was Amnon Shamosh, brother of Yitzhak, the ''honest'' emissary who was unwilling to steal the manuscript in 1943 when he had the chance. Amnon is one of Israel's best-known authors, achieving fame when his novel ''Michel Ezra Safra & Sons'' was adapted as a television series that nearly everyone in the country watched in the early 1980s, on what was then the only TV station in Israel. It told the tale of a family of bankers from Aleppo who lost everything and were forced to flee to Israel after the establishment of the state. Early in the story, the family patriarch rescues the Aleppo Codex from a fire and takes it to Nice, France.

Shamosh's book and the TV series imbued the ''Arab'' Jews with newfound pride, illustrating to the Ashkenazim that they too came from a rich cultural tradition. ''Suddenly they discovered that the Jews from the Arab lands were not primitive,'' Shamosh told me. ''That there were Jews here who were educated, shrewd and rich.''

Today, Shamosh lives in the Maayan Barukh kibbutz, near the Lebanese and Syrian borders. He is nearly blind; his thick glasses and a special electronic magnifying glass enable him to read, little by little, from the books that line his living-room walls. ''A short while after the novel came out,'' he told me, ''I got a call from Edmond Safra, who asked me to come and see him at his office in Geneva.'' Safra, a billionaire in the finance industry whose family came from Aleppo, was a great believer in metaphysical forces, and when he learned of Shamosh's novel -- and that his family's name had been mentioned in connection with the removal of the codex -- he was gripped with terror. In Geneva, he was waiting for Shamosh with an open checkbook. ''Here,'' Safra told him. ''It's yours. Write in it any amount that you want. I'll buy all the books that are out there, and then you can print as many as you want with a different name.''

Shamosh said: ''I tried to explain to him that it was all fictional, but I couldn't get through to him. Safra said to me: 'I don't want to provoke the evil eye. This thing is going to bring about my death in terrible circumstances.' ''

The Ben-Zvi Institute commissioned Shamosh, because of the success of his novel, to write a scholarly work on the codex. He submitted a manuscript containing the findings of his research, which included severe criticism of Murad Faham's conduct and of the institute itself, for dereliction in their handling of the volume. Shamosh smiled when he recounted what happened when the institute received his manuscript: ''There was a chapter on the conduct of the institute they wanted me to remove.''

He said he told them he was prepared to expunge his criticism of Faham, but he would not remove his findings on the neglect of the codex until he saw with his own eyes that restoration was being done on it. Later, a philanthropist from the Aleppo community in New York donated money for the restoration of the book, and it was transferred in an armored van to the conservation laboratory of the Israel Museum.

During the course of the work, which took six years, Maggen, the head of the museum's paper-conservation lab, discovered something of major significance: Until then, the story that had been officially told was that the missing pages were destroyed in the blaze at the Aleppo synagogue, a theory supported by the purple signs of charring that existed on the edges of the rescued pages. But Maggen found that the purple markings were not caused by fire at all, but rather by a mold that discolored the pages. If these pages weren't damaged by fire, then how could the others have been destroyed?

For quite some time, suspicion was directed at the members of the Aleppo community -- that one or several of its members had taken the missing pages from the synagogue after the fire, or that those who had hidden the codex for 10 years before it was smuggled out of Syria had helped themselves to souvenirs. These theories made sense given the common belief that even a fraction of the codex had the power to protect its owner.

Rafi Sutton, who played a leading role in Israeli intelligence agencies, was born in Aleppo and lived there throughout his childhood. He is 80 now and lives in a small city outside Jerusalem. When I visited him at his home in May, he recalled the day of his bar mitzvah in 1945. ''They gathered us, 15 children, stood us in a line, a few meters from the safe, and opened it with two keys,'' he said. ''Many of us were gripped by a powerful trembling, because since we were babies, we'd been taught that a plague would kill whoever didn't relate to the book with suitable respect.''

A few days after the attack on the Aleppo synagogue, Sutton and his friend, Leon Tawil, went to examine the smoldering ruins. Tawil found a page with scripture on it and put it in his pocket. Later, at home, his father told him that he believed the leaf came from the codex. Tawil took it with him when he fled from Syria to Lebanon in 1950, and from there boarded a ship that took him to the United States, where he joined the Aleppo congregation in Brooklyn. He gave the page to his aunt, and when she died, her daughter Renee inherited it and gave it to her niece, whose son, Aryeh Romanoff, is today a judge in the Jerusalem District Court. Romanoff told me that an aunt from America -- Renee -- once came to visit and ''brought with her this page and said she'd been told that it belonged to some sacred book.'' He added: ''My mother didn't know what it was and ended up calling in an expert from the National Library. He came, opened the package and was out of his mind with happiness. 'It's the Aleppo Codex! It's the Aleppo Codex!' He was almost jumping with joy.''

In 1988, Menahem Ben-Sasson, deputy director of the Ben-Zvi Institute, located another fragment of a page, jealously guarded by an elderly man named Shmuel Sebbagh, who lived in Brooklyn. It was part of the Book of Exodus, which relates how, after the Nile turned to blood, Aaron stretched forth his staff, causing a plague of frogs to descend on Egypt. ''I called him and introduced myself,'' Ben-Sasson told me earlier this month in Tel Aviv. ''He didn't say hello or ask me what I wanted. He just told me firmly: 'Forget about it. I do not intend to give it to you.' '' Sebbagh wouldn't say where he obtained the fragment, which he had laminated and kept in his pocket at all times. Only after his death, and in exchange for a large and undisclosed sum of money, did the Sebbagh family agree to hand it over to the Ben-Zvi Institute. It was put on display in the Shrine of the Book for the first time last month.

These are the only missing parts of the codex that have been located to date, yet the efforts to discover more persist. In the mid-1990s, Mossad, with some involvement from the C.I.A. and the U.S. State Department, conducted a large-scale secret operation to get the last Jews out of Syria, including the devastated Aleppo community, many of whose members believed that the curse of the codex had befallen them. As part of that operation, the Mossad managed to smuggle Torah scrolls and other sacred books back to Israel, but efforts to locate the missing codex pages led only to dead ends.

Amnon Shamosh told me that an anonymous source promised to pay for the acquisition of any codex pages. With this promise in hand, Shamosh turned to Vartan Gregorian, who was then the president of the New York Public Library. Gregorian agreed to place a notice in a journal for collectors of Judaica announcing that he would purchase pages from the codex. Shamosh, along with other scholars, made the rounds of wealthy communities of Aleppo Jews in Panama, S?Paulo, Buenos Aires and New York, and were permitted to address congregations at Friday-night services. ''Someone here may be in the possession of a piece of parchment without knowing of its great value for the Jewish people,'' they would say. ''Perhaps someone here has heard a story told by a grandfather from Aleppo. Please help us.'' One of those emissaries was Ben-Sasson, who obtained a special judicial ruling from the chief rabbi of Israel reinstating the curses associated with the codex, only now they worked the other way: against anyone who was secretly holding on to it. ''The holy manuscript must be returned to Jerusalem,'' he pleaded, but he soon realized that there was no point to his efforts. ''The members of the community explained to me that, with all due respect to the chief rabbi and the power of his ruling, the faith of the Jews of Aleppo in the power of the codex is greater by far, and they believe that even a tiny fragment from it bestows great strength of health and well-being upon them.''

Several people I interviewed for this article claimed that they had seen parts of the codex hidden away by former Aleppo residents or in the hands of collectors, but to date, all efforts to investigate such leads have been unsuccessful.

In 1989, Israel Television appointed Sutton to investigate the whereabouts of the missing pages. Sutton, after immigrating from Aleppo, served as an intelligence officer and a Mossad operative with considerable distinction. He even had experience rescuing precious documents: On June 6, 1967, in the midst of the Six Day War, Sutton, who was responsible for running agents in enemy territory, received an urgent cable instructing him to find an antiquities dealer named Dino, whom they suspected was in possession of one of the Dead Sea Scrolls.

Sutton and other officers arrested the man and his son, who both emphatically denied the allegation, but after learning that a conversation they had in their jail cell about the scroll in question had been recorded, they confessed. ''He realized that the game was up and began cooperating,'' Sutton told me when we met in his home near Jerusalem in late May. ''He took us to his home and began counting floor tiles. Five this way, four that way. Then he finds it and brings a plunger for clearing drains, uses it to lift two tiles, under which there's a layer of straw. I tell him, 'Pick it up yourself,' because it may be booby-trapped. He picks up the straw, and under it there's a shoe box. I go, 'Lift it.' So he lifts it. I go, 'Open it.' Inside, there's more straw and two cylinders wrapped in cellophane and tied with red ribbon.'' They turned out to be the Temple Scroll, the longest of the Dead Sea Scrolls.

It seemed fitting, then, that Sutton should lead a worldwide investigation into the mystery of the missing codex pages, and the conclusions of his inquiry were groundbreaking. A number of testimonies indicated that the codex survived the fire intact, or almost intact, and that it had also reached Israel intact. The suspicion now shifted from the Aleppo Jews to whoever held it in their possession after Murad Faham brought it to Israel. Shortly before he died, Shlomo Zalman Shragai, whose colleague took the codex from Faham at the port in Haifa, told Sutton that the manuscript reached him almost intact. Earlier this month, Shragai's son told Ezra Kassin, as part of Kassin's ongoing investigation, that he was present when the codex was brought to their home and that he definitely saw that ''only a few pages were missing, three or four, all the rest were intact.''

Meir Benayahu, who was Ben-Zvi's personal secretary when the codex reached him and who was also the first director of the Ben-Zvi Institute, had drawn up a memo upon receipt of the codex. Given Benayahu's scholarly background and the historical significance of the codex, you would assume that there would be precise notes detailing its condition and the number of pages it contained, and yet apart from the name Keter Aram Tzova -- the manuscript's Hebrew name -- no further details were provided. Furthermore, shortly after the codex was delivered, Ben-Zvi supplied the editors of the Hebrew Encyclopedia with incorrect information, which he had been given by Benayahu, regarding the number of pages. Only after some time was it discovered that almost half of the codex was missing.

Which leads us to Shlomo Moussaieff, a London jewelry mogul and one of the biggest collectors of Judaica in the world. Moussaieff, who refused to respond to my queries, told officials from the Ben-Zvi Institute, as well as Ezra Kassin, who is now the head of the Aleppo Jews in Israel, and Matti Friedman, the author, that in the mid-1980s two ultra-Orthodox Jews approached him in the lobby of the Jerusalem Hilton. One of them, Haim Schneebalg, was well known to him. Schneebalg was a shrewd dealer in ancient Jewish manuscripts and happened to be an acquaintance of Meir Benayahu. He was considered to be one of the most expert and reliable dealers in the field, who handled only highly valuable finds. When he and his partner approached Moussaieff, Schneebalg was carrying a briefcase. Moussaieff recalled the following exchange, which appears in Friedman's book.

''Shlomo, come quick, we have something for you,'' Schneebalg told him.

''What do you have?'' Moussaieff asked.

''Quiet. We know that you'll be quiet and won't tell anyone,'' Schneebalg said. The three men went up to a hotel room, where Schneebalg opened the briefcase.

In an interview shown in 1993 on Israel national TV, Moussaieff recalled: ''They put the suitcase on the bed, opened it, opened a silky paper that was covering it. All of a sudden, my eyes popped out. I saw between 70 and 100 parchment pages lying on top of each other, inscribed with black ink that because of time had reddened slightly. In large letters, about double the size of a Torah scroll's letters, with vowels. The handwriting was a little like a dancing handwriting. . . . I have no doubt that what I saw was part of the Aleppo Codex.''

The two argued over the price, and Moussaieff finally offered to buy only part of the manuscript, to which Schneebalg replied that it was all or nothing. In retrospect, Moussaieff would admit that he made a huge mistake. As he told a reporter from an Israeli newspaper in 1993: ''I was greedy. I tried to make a lower offer, thinking perhaps they would agree to take less. The price they were asking wasn't sky-high, but I tried to bargain with them. That's how I lost the codex. Another buyer paid $100,000 more than I was ready to pay. . . . It's with an ultra-Orthodox Jew in London. I have no intention of revealing his name.''

Ben-Zvi Institute officials say they tried to persuade Moussaieff to give them his name. ''He did not admit anything,'' Yom Tov Assis, the current director of the institute, told me. ''I asked him to help me, but he kept mum, wouldn't answer and seemed very hostile.''

Nor will Schneebalg ever reveal who bought the codex from him. On Aug. 16, 1989, in a room at the Plaza Hotel in Jerusalem, his body was discovered with blood dripping out of his nose. The person who rented the room, under the name Dan Cohen, had vanished, and the details he gave when checking in turned out to be false. Schneebalg's ultra-Orthodox family refused to have a forensic autopsy carried out because of religious precepts, and the cause of death was never conclusively established. Many in the world of Judaica believe that he was murdered because of his involvement with the codex.

During his investigation, Sutton came to the conclusion that the theft was perpetrated after the codex arrived in Israel, and he said he had identified the thief. He devised an international sting operation to retrieve the missing pages, which would need financing, beyond what the TV station that had commissioned the investigation could supply.

In the early 1990s, Sutton happened to meet Edmond Safra in Jerusalem's King David Hotel. Sutton promised him that if Safra would finance the sting operation to hunt for the missing pages, he would alleviate Safra's anxiety by making it known on live television that his family had no connection to the codex. ''And indeed, just as I had promised,'' Sutton told me, ''I declared to the entire nation on live TV that the codex was not in the hands of the Safras. Amnon Shamosh was sitting in the studio, and I turned to him and said, 'Right, Amnon?' and he nodded his head and said: 'Right, right. It's all fiction.' After that I never heard a word from dear Edmond again. He disappeared, gone, and the operation was called off.''

Edmond Safra, whose fear of the evil eye had haunted him all his life, died in a terrible fire in his penthouse in Monaco in December 1999.

By virtue of the standing and prestige of President Ben-Zvi, some 3,000 manuscripts originating from Arab lands, some of them of major significance, have been deposited at the Ben-Zvi Institute. In contrast to the Aleppo Codex, most of these documents were donated willingly, in the confidence that the institute would protect and preserve them. As a result of Matti Friedman's investigation, it has now emerged that throughout the 1950s and 1960s, a systematic plundering of ancient books and manuscripts not related to the codex took place there.

In 1970, Meir Benayahu ceased working as director of the institute for reasons that are unclear. Benayahu was the son of Yitzhak Nissim, the Sephardic chief rabbi of Israel in the 1960s, and the brother of Moshe Nissim, a politician who served in several cabinets. Benayahu, who died in 2009, was a leading collector of sacred books, and it was he who wrote the uncharacteristic memo for the receipt of the Aleppo Codex.

Moshe Nissim told me that his brother terminated his employment at the institute of his own volition. Benayahu left amid a power struggle over the leadership and location of the institute. Around the same time, sources there say, there was growing suspicion that he had been stealing manuscripts. It was Benayahu, in fact, who was the target of Sutton's sting operation. ''We used to call him the 'Thief of Baghdad,' '' a source told me.

Benayahu never left an orderly catalog of incoming books and manuscripts, so it is difficult to ascertain exactly what went missing, except from various scattered notes and requests by donors to view the documents they had donated. Such a request was recently submitted by the Silvera family of New York, in the form of a sharp complaint to the Israeli State Comptroller. In 1961, David Silvera, a banker and merchant, donated a rare manuscript of the Hebrew Bible from Corfu. Ben-Zvi himself signed one of the receipts for the manuscript on May 15, 1961. Meir Benayahu signed another on the same date. The book has vanished.

The institute has taken an inconsistent stand on Benayahu. On the one hand, Assis, the director, refuses to allow access to Benayahu's personal dossiers. He keeps them in his safe and has said for months that he has ''not managed to look at them.'' On the other hand, he also said: ''We have done all we can within the law to retrieve the books that have disappeared. Do you imagine that if we knew where a certain book was located, we wouldn't try to get it back?''

In an emotional telephone conversation with me, Moshe Nissim said: ''For 40 years, my brother was considered the most honest of men, the most righteous, a man who gave his life to the study of the culture and who put at the disposal of scholars his entire private collection. Forty years, and no one complained. Everyone just heaped prizes and praise on him. And now, all of a sudden, some scoundrels are trying to smear his good name.''

Where then is the missing section of the Aleppo Codex? Sutton says the subject has become so sensitive that even if the person now in possession of it wanted to sell it, he would not do so for fear of his own safety.

Menahem Ben-Sasson, today the president of Hebrew University, told me: ''The codex has become so important that anyone who's holding it, if anyone is, may never agree to take it out of hiding, not for all the money in the world. It may be that generations will go by before his sons or his sons' sons will be free of the sense of guilt for holding on to it and will deliver it to its natural resting place, the Shrine of the Book in the Israel Museum in Jerusalem.''

Responding to the charge that Ben-Zvi stole the codex from the Aleppo Jewish community, Assis said: ''I know of no community and no synagogue that could have looked after the codex better than we do at the Ben-Zvi Institute. And the question arises, of course, who here represents the Jews of Aleppo? Me, an Aleppo-born head of the Ben-Zvi Institute. I belong to them, and I belong to the institute. After all, if the book had not reached Israel, it would probably be sitting right now in some museum being shelled by the guns of Bashar al-Assad.''