Even if these were the only ingredients, the story would still be intriguing enough for a Robert Ludlum thriller. But an added element is making the scandal that has rocked the world of international finance one of the most compelling real-life mysteries of the century: the involvement of the Istituto per le Opere di Religione (I.O.R.), better known as the Vatican bank.

Founded in 1942 to invest and increase the funds given to the Holy See for religious works, the I.O.R. is much like any other international commercial bank. It accepts savings and checking accounts, transfers funds in and out of the Vatican and makes investments. There are, however, some interesting differences in the bank, which is tucked away in the medieval tower of Sixtus V. Depositors must be connected with the Vatican. The list of those eligible includes members of the Curia (the Pope has a personal account, No. 16/16), the 729 permanent residents of Vatican City, and a small group of clergymen and laymen who have regular business dealings with the Vatican. No others need apply. The bank's assets are thought to be modest by international standards. For that reason, the scandal is especially threatening to the I.O.R.: Italian authorities say the bank may be liable for much of the millions the Banco Ambrosiano Group owed to international banks.

The scandal has also brought a wave of unwelcome attention to the Vatican bank's American-born president, Archbishop Paul Marcinkus. So far no one has openly accused Marcinkus of any illegal acts. But he is one of three Vatican officials under investigation by Italian authorities, who have indicated that Marcinkus could ultimately be charged. Serious questions are also being raised about his judgment and competence, specifically about his willingness to let the Vatican bank and its good name be used by international wheeler-dealers. At least eleven other official inquiries into Banco Ambrosiano's affairs are under way, in Italy, Britain, Switzerland, Luxembourg, the Bahamas and Peru. As those investigations stumble forward, the archbishop's once promising career is endangered, and the affair threatens to become an embarrassment for Pope John Paul II.

Simmering for more than a year, the scandal came to a boil last June 18, when the body of a man was found hanging from London's Blackfriars Bridge, his toes just touching the surface of the muddy Thames. The dead man's pockets contained some $13,000 in various currencies, as well as 12 lbs. of bricks and stones. He was identified as Roberto Calvi, 62, the president of Banco Ambrosiano of Milan, the largest private banking group in Italy, with operations in 15 countries. Authorities in Italy, in the Vatican and throughout the international banking community were stunned by the news. Calvi, who had disappeared mysteriously from Italy a week earlier, was the architect of a financial house of cards, and his death brought the structure tumbling down.

Italian authorities have since ordered the liquidation of Banco Ambrosiano and declared the institution bankrupt. The government has also been pressing the Holy See for a fuller disclosure of its role in the bank's affairs, thus rekindling the age-old tension between Italy and the Vatican, an independent entity that occupies 108.7 acres in the center of Rome. The Bank of Italy, the nation's central bank, has agreed to cover only part of Banco Ambrosiano Group's $1.2 billion shortfall, and is suggesting that the I.O.R. may have to come up with at least some of the money. Part of the reason for the Bank of Italy's stand is to put pressure on the Vatican to bring its bank into line with Italian banking regulations. The Bank of Italy has long been resentful of the I.O.R.'s status as an unregulated "offshore," or foreign, bank in the heart of the country. In addition, Archbishop Marcinkus and his two principal lay assistants, Managing Director Luigi Mennini, 71, and Chief Accountant Pellegrino de Strobel, 70, are under investigation by Italian authorities in connection with the possibly fraudulent bankruptcy of Banco Ambrosiano.

The Vatican, citing its status as a sovereign state, has so far declined to cooperate with the Italian authorities, and Marcinkus has remained inside the Vatican, where he cannot be questioned by the government. But Agostino Cardinal Casaroli, the Vatican's Secretary of State, has named three respected international bankers, all prominent Catholic laymen, to examine the I.O.R.'s role in the scandal.* Casaroli has pointedly not suggested that Marcinkus did anything illegal. At the same time, however, the Archbishop of Florence, Giovanni Cardinal Benelli, a former Vatican Under Secretary of State, has told the Italian magazine Il Sabato that "if there was any imprudence, it was because of incompetence and inexperience." Added Benelli: "The fact that Archbishop Paul Marcinkus is a friend of the Pope's doesn't mean that he has to remain in the post."

The son of impoverished Lithuanian parents who immigrated to Cicero, Ill., Archbishop Marcinkus had enjoyed a steady rise in the Vatican hierarchy before the scandal broke. After taking a degree in canon law at Rome's Pontifical Gregorian University, Marcinkus joined the Vatican's State Secretariat in 1952 and soon caught the eye of Archbishop Giovanni Battista Montini, who was to become Pope Paul VI in 1963. The new Pontiff made the tall (6 ft. 3 in.), burly American cleric part of an intimate circle of papal advisers. In 1964 the Pontiff selected Marcinkus, a born organizer, to be his advanceman for trips abroad. During the visit of Paul VI to Manila in 1970, the athletic Marcinkus helped to subdue a Bolivian artist disguised as a priest who tried to stab the Pope. Paul VI put him in charge of the Vatican bank in 1969. Last year John Paul II gave Marcinkus the task of running Vatican City's administration; with the new job came the title of archbishop and the prospect that Marcinkus would some day become a Cardinal.

Noting the pending investigations, Marcinkus has declined to discuss the Ambrosiano affair in detail. After contacts with top Vatican officials and conversations with Marcinkus, TIME Correspondent Wilton Wynn reports that the Vatican claims its relationship with Calvi and Banco Ambrosiano involved only normal banking operations. As for Marcinkus, he is still at his Vatican bank post, expressing confidence that the storm will pass. Says he: "The old archbishop is tranquil. His conscience is clear."

Whether Marcinkus has good reason for such tranquillity may not be immediately known. The investigation to determine just what Calvi did with the huge sums his banks borrowed and to figure out who is liable for the losses that resulted is likely to last for weeks. But the outlines of the scandal have already begun to emerge.

Calvi began spinning his web in 1971, shortly after he became director-general of Banco Ambrosiano. An employee of the bank for 24 years, Calvi was determined to transform it into a major international financial institution from a relatively small regional bank with strong religious overtones (until ten years ago, would-be shareholders had to present baptismal certificates to prove their Catholicism). One of his initial steps was to form a Luxembourg holding company, Compendium, which later became Banco Ambrosiano Holding. The advantage of a foreign subsidiary: it is not subject to Italy's banking regulations. Calvi's next moves were to use the Luxembourg holding company to set up banks in Switzerland, the Bahamas, Peru and Nicaragua, and companies in Panama, Luxembourg and Liechtenstein.

Under local laws, the Panamanian firms could be started with as little as $10,000 in capital, but could be used to borrow far greater sums on world financial markets. Calvi launched at least a dozen such "shell" companies in Panama, listing employees of his Bahamas bank, including the switchboard operator, as directors and officers.

The Vergil who first guided Calvi through the descending circles of these and other transactions was Michele Sindona. A onetime Italian financier and Vatican financial adviser, he is currently serving a 25-year prison sentence for fraud in connection with the 1974 collapse of New York's Franklin National Bank (see box). Sindona became connected with the Vatican in the mid-1960s and later helped Pope Paul VI divest the church of its holdings in several large companies.

In 1971, Sindona introduced Calvi to Marcinkus. Sindona and Calvi hoped to use Marcinkus for their own purposes, and the bankers and the churchman obviously found it advantageous to do business together. Although the Vatican bank denies it had much to do with either Sindona or Calvi, the I.O.R. eventually became Banco Ambrosiano's fourth-largest stockholder, acquiring over the years at least 794,390 shares, or 1.589% of the bank's stock. A few months after Sindona and Calvi set up the Bahamian bank in 1971, a "Mr. Paul Marcinkus" was listed as a director. "We used his name a lot in business deals," Sindona said. "I told him clearly that I put him in because it helps me get money."

What the I.O.R. may have obtained in return remains to be learned. But according to Sindona, the Vatican bank initially received 2.5% of the Bahamian bank's stock. Vatican officials told TIME that the stake in the Bahamian bank eventually rose to 8% and that the church's interest in Banco Ambrosiano Holding in Luxembourg was 4%.

The I.O.R., according to Sindona, regularly moved funds out of the country for Banco Ambrosiano, which was restricted from acting on its own by Italian law. Sindona also asserts that in return for such favors, Calvi's banks paid the I.O.R. an interest rate on its deposits that was one percentage point higher than the rate other customers received. Vatican officials flatly deny that the I.O.R. ever helped transfer funds abroad for Italians.

As Sindona's fortunes fell (his Banca Privata Italiana collapsed in 1974, the same year that his American operation fell apart), Calvi's rose. He was named president of Banco Ambrosiano, and acquired more and more companies. The press dubbed the publicity-shy Calvi "God's banker" for his ties to the I.O.R. He became known as the man who had taken over the disgraced Sindona's role as the Vatican's lay financial partner.

But Calvi's luck soon ran out. In the late 1970s, suspicious of the way in which he was operating in the international money market, the Bank of Italy ordered him to put his confusing array of banks under the single name of Ambrosiano. Some Italians also became nervous about another Calvi acquisition: his purchase of 40% interest in Italy's 73-year-old Rizzoli publishing company and with it a piece of the Milan-based Corriere della Sera, Italy's largest, most respected daily newspaper. Businessmen who were already uneasy about Calvi's connections with the Vatican feared that he might turn the independent Corriere to his own purposes, perhaps to punish his enemies with unfavorable coverage or commentary. Some Italians believe that Calvi's growing power led influential businessmen and public officials to begin to push for his downfall.

Calvi's real problems had begun in 1978, when the Bank of Italy conducted an extensive audit of his financial empire. The examiners noted unorthodox operations and complained that Ambrosiano affiliates were carrying out "all types of operations outside of controls." Ominously enough, the investigators also noted that they could not separate Ambrosiano holdings from Vatican holdings because of the complex interlocking relationships between them.

That audit proved to be inconclusive, but it led to a second, completed earlier this year, that uncovered $1.2 billion in unsecured lending. Calvi was buying up Ambrosiano stock, possibly using money borrowed on international financial markets by Ambrosiano and its subsidiaries, in an attempt to strengthen his grip on the parent bank. During 1978-79 and in 1981, Ambrosiano and its subsidiaries raised about $1.2 billion. In these years the banks lent at least $800 million to low-capitalized shell companies in Panama, Luxembourg and Liechtenstein. The shell companies, in turn, used about $400 million to buy stock in Banco Ambrosiano and other securities. All or part of yet another $400 million appears to have been funneled through these same companies to finance South American deals. By June 1982 the shell companies owed Banco Ambrosiano banks about $1.2 billion—the $800 million they had borrowed plus $400 million in accrued interest. Calvi's scheme, and his empire, collapsed because Italian lire, in which the Ambrosiano stock was denominated, failed to keep pace with the rising value of dollars in which the loans had to be repaid.

In 1981 Calvi and several colleagues were indicted for illegally exporting $26.4 million in capital from Italy during 1975 and 1976. Calvi was found guilty in July 1981, fined a total of $11.7 million and sentenced to four years in jail. He was released pending appeal.

While Calvi was being prosecuted for the illegal export of capital, police raided the sumptuous Arezzo villa of Licio Gelli, a Tuscan-born businessman with financial and right-wing political links to South America who served as Grand Master of a Masonic lodge known as Propaganda Due, or P2. Police found Calvi's name, along with those of other prominent Italian and South American politicians, military officers and businessmen (including Sindona), on the secret membership list. P2 was trying to support anti-Communist movements in South America and subvert the Italian state by taking control of its institutions through the lodge's influential membership. The discovery of P2 and its flock of politicians helped to topple the government of Prime Minister Arnaldo Forlani in 1981.

Even as he appealed his four-year jail sentence this summer, Calvi continued to try to make new deals and extricate himself from the hole he had dug. Barely a month after his conviction, in fact, he asked the I.O.R.'s aid as he sought ways to help pay off the outstanding loans made by his shell companies. Though he had been convicted of a financial crime, Calvi was still made welcome at the Vatican bank and other banks. Marcinkus' defense is that he was newly reconfirmed as president of Banco Ambrosiano, and the bank's balance sheet was approved at the end of 1981 by the Bank of Italy.

The I.O.R. supplied Calvi with "letters of patronage" (called comfort letters by bankers), documents stating that the shell companies were controlled, either directly or indirectly, by the I.O.R. By issuing such letters, the Vatican bank was in effect vouching for Calvi's creditworthiness. The letters do not legally obligate the Vatican bank to pay off debts of the companies in question. But the letters do, according to some banking officials, imply a moral obligation. Marcinkus did not sign the letters, but he has taken full responsibility for them.

Even more troublesome for the I.O.R., investigators have discovered what has been dubbed a "liberating letter," written by Calvi to the I.O.R. five days before the letters of patronage were issued. The liberating letter in effect negates the letters of patronage and relieves the Vatican bank of any responsibility for the companies in question. Yet this letter was never made known to the Ambrosiano Latin American banks that lent money to Calvi's shell firms. The liberating letter thus gives the arrangement between Calvi and the I.O.R. the appearance of a conspiracy to withhold essential information from the lending banks. The various letters suggest that Marcinkus allowed the Vatican's name to be used in a questionable way in order to influence the bankers. The letters were written after loans had been made to the shell companies, and, according to Vatican officials, Marcinkus claimed the letters were for "internal use." Calvi needed them to appease the directors of Ambrosiano's Peruvian bank, who questioned the value of the shell companies.

The I.O.R.'s letters of patronage seemed to help Calvi, at least temporarily. But in the end even this ploy failed. When Calvi asked the I.O.R. to renew the letters, which expired in June 1982, Marcinkus turned him down. Another setback soon followed. After the Bank of Italy demanded that Ambrosiano account for its huge foreign lending, the bank's directors overruled Calvi and agreed to cooperate.

His world collapsing about him, Calvi fled Italy with a false passport, flying first to Austria, then to England. There, according to the two confidants who were with him, a traveling companion and a longtime business partner, he remained in seclusion in a rented apartment in London's Chelsea section. On June 17, Banco Ambrosiano's board of directors voted to strip Calvi of his powers, and the Bank of Italy appointed a commission to run Ambrosiano. That same day, Graziella Corrocher, 55, Calvi's longtime secretary—who, says Sindona, also kept the books for P2—plunged to her death from the fourth floor of the bank's Milan headquarters. She left behind an apparent suicide note saying, "May Calvi be double-cursed for the damage he has caused to the bank and its employees."

On the day after his secretary's death, Calvi was found hanging in London. In the absence of evidence to the contrary, British authorities ruled Calvi's death a suicide. But some Italians saw sinister significance in the fact that he was dangling from Blackfriars Bridge: members of P2 dress in black and address each other as "friar." Both Sindona and Calvi's son Carlo, 30, believe that the banker was killed. So does Franco de Cataldo, a member of an Italian parliamentary commission investigating P2, who declared last week on the floor of the Chamber of Deputies: "It appears ever more probable that Calvi was murdered."

In the wake of Calvi's death, a number of his associates reportedly fled Italy for South America and took large sums of money with them. Flavio Carboni, the business partner who had met with Calvi in London, was arrested in Switzerland. An Ambrosiano attorney says "many millions of dollars" were transferred to Carboni's Swiss accounts by Calvi some months before the trip to London.

The circumstances of Calvi's demise are only one of the unsolved mysteries in the Ambrosiano scandal. Among the others:

- How much of Banco Ambrosiano does the I.O.R. really own? Italian financial sources suggest that I.O.R. ownership may run as high as 10%. Vatican officials insist that the figure is exaggerated, but have left open the possibility that the Vatican bank's ownership may exceed the officially reported 1.589%.

- What, if any, was the extent of church officials' knowledge of P2? Lodge Grand Master Licio Gelli, who has gone into hiding, was a business associate of Calvi's. Sindona claims that Gelli had long championed the practice of funding opponents of Communism in order to help the cause of Catholicism, and that Calvi was the paymaster for Gelli's activities.

- What is the Vatican bank's liability in the Banco Ambrosiano failure? The I.O.R. could find its creditworthiness undermined if it refuses to help make up the losses. Italian officials expect the Vatican to pay part of the losses.

Another question that the Vatican must answer, if only to itself, is: Should the church's own bank be so deeply involved in the rough-and-tumble of high-risk international finance? Pope Paul VI, feeling that the church should not only be poor, but be "seen to be poor," moved in 1969 to adopt a lower financial profile by relinquishing the church's controlling interests in Italian companies and shifting to investments outside Italy. Through the Ambrosiano scandal, Marcinkus has clearly raised the church's profile.

High-ranking Vatican sources have already suggested that Marcinkus will be staying behind when Pope John Paul II travels to Spain next month. The reason is that Vatican officials want the archbishop around to answer any questions that might arise concerning his role in the Banco Ambrosiano affair.

But there may be more to the decision than that. Some Vatican officials are concerned that Marcinkus, his subordinates Mennini and De Strobel, or all three, might be indicted. There is concern in the Holy See that they could be arrested if they should so much as step outside the Vatican, thus setting the stage for a legal battle between the church and civil authorities. The ultimate decision about Marcinkus' fate rests with the man in whose name one of the inquiries is being conducted: Pope John Paul. The Holy Father may choose not to do anything until the Holy See's own investigation is completed. Even then the lesson of Paul Marcinkus may prove to be nothing more than what well-intentioned clerics have been learning for centuries: trying to serve both God and mammon can be a difficult task indeed. —By Peter Staler. Reported by Jonathan Beaty/New York and Barry Kalb/Rome with other bureaus

*The trio, already dubbed the "three wise men" by the Italian press, are Joseph Brennan, 71, chairman of the executive committee of New York's Emigrant Savings Bank; Phillippe de Week, 63, former president of the Union Bank of Switzerland; and Carlo Cerutti, 70, vice president of STET, the Italian national telecommunications company.