THE PERFECT MARK.(advance-fee fraud offered to John W. Worley from Nigeria )

Late one afternoon in June, 2001, John W. Worley sat in a burgundy leather desk chair reading his e-mail. He was fifty-seven and burly, with glasses, a fringe of salt-and-pepper hair, and a bushy gray beard. A decorated Vietnam veteran and an ordained minister, he had a busy practice as a Christian psychotherapist, and, with his wife, Barbara, was the caretaker of a mansion on a historic estate in Groton, Massachusetts. He lived in a comfortable three-bedroom suite in the mansion, and saw patients in a ground-floor office with walls adorned with images of Jesus and framed military medals. Barbara had been his high-school sweetheart--he was the president of his class, and she was the homecoming queen--and they had four daughters and seven grandchildren, whose photos surrounded Worley at his desk.

Worley scrolled through his in-box and opened an e-mail, addressed to "CEO/Owner." The writer said that his name was Captain Joshua Mbote, and he offered an awkwardly phrased proposition: "With regards to your trustworthiness and reliability, I decided to seek your assistance in transferring some money out of South Africa into your country, for onward dispatch and investment." Mbote explained that he had been chief of security for the Congolese President Laurent Kabila, who had secretly sent him to South Africa to buy weapons for a force of elite bodyguards. But Kabila had been assassinated before Mbote could complete the mission. "I quickly decided to stop all negotiations and divert the funds to my personal use, as it was a golden opportunity, and I could not return to my country due to my loyalty to the government of Laurent Kabila," Mbote wrote. Now Mbote had fifty-five million American dollars, in cash, and he needed a discreet partner with an overseas bank account. That partner, of course, would be richly rewarded.

Mbote's offer had the hallmarks of an advance-fee fraud, a swindle whose victims are asked to provide money, information, or services in exchange for a share of a promised fortune. Countless such e-mails, letters, and faxes are sent every year, with a broad variety of stories about how the money supposedly became available (unclaimed estate, corrupt executive, and dying Samaritan being only a few of the most popular). Worley, who had spent his adult life advocating self-knowledge and introspection, seemed particularly unlikely to be fooled. He had developed a psychological profiling tool designed to reveal a person's "unique needs, desires and probable behavioral responses." He promised users of the test, "The individual's understanding of self will be greatly enhanced, increasing the potential for a fulfilled and balanced life." And Worley was vigilant against temptation. Two weeks before the e-mail arrived, he had been the keynote speaker at his eldest granddaughter's graduation from the First Assembly Christian Academy in Worcester, Massachusetts. He cautioned the students about Satan, telling them, "He's going to be trying to destroy you every inch of the way."

Still, Worley, faced with an e-mail that would, according to federal authorities, eventually lead him to join a gang of Nigerian criminals seeking to defraud U.S. banks, didn't hesitate. A few minutes after receiving Mbote's entreaty, he replied, "I can help and I am interested." His only question was how Mbote had found him, and he seemed satisfied with the explanation: that the South African Department of Home Affairs had supplied his name. When Worley attributed this improbable event to God's will, Mbote elaborated on the story to say that Worley's name was one of ten that he had been given, and that it had been pulled from a hat after much prayer by someone named Pastor Mark. (A more likely possibility is that his e-mail address was plucked from an Internet chain letter, which he received and passed on, that promised a cash reward from Microsoft to anyone who forwarded the letter to others.) In e-mails, phone calls, faxes, and letters during the ensuing weeks, Mbote laid out the plan: If Worley would pay up-front costs, such as fees to a storage facility where the cash was being kept, and possibly travel to South Africa to collect the money, he would receive thirty per cent, or more than sixteen million dollars.

Worley told Mbote that he lived his life with the "utmost integrity" and didn't want to jeopardize that. He also said that he couldn't fund the operation. (Though he would report nearly a hundred and forty thousand dollars in income in 2001, he had declared personal bankruptcy in the early nineties, had relatively little saved for retirement, and wanted to help his grandchildren through college.) No problem, Mbote answered; "investors" would provide up to a hundred and fifty thousand dollars for airfare and other expenses needed to move the money to the United States, ...