Britain was great to Sergei Kapchuk. After fleeing Russia to avoid prosecution for alleged fraud in 2005, then escaping from Abu Dhabi on the back of a camel to avoid extradition in 2010, he landed at Gatwick airport with his twin brother’s passport. He won political asylum within four months. For the next eight years, the former regional lawmaker and factory owner from Yekaterinburg led a charmed life in London as Sergi Windsor, dating socialites such as Miss Russia 2008 and partying with other self-imposed exiles whose income streams were always a bit of a mystery. Then things got really weird.

In March, a year after Russia put him on the country’s so-called London List of most-wanted fugitives, Kapchuk-Windsor went on the run again — this time back into the arms of the countrymen he once feared. He worried Britain wanted to kill him and finger the Kremlin for the crime. Just about everyone contacted for this article, including fellow exiles and even a KGB veteran, say Kapchuk’s claim that U.K. operatives are hunting Russian emigres is outlandish. But his narrative, told over multiple interviews in Moscow, fits the Kremlin line that even former fugitives are safer at home these days than in the West, where Russian wealth is increasingly vulnerable to sanctions. Russian sleeper agent, British mole, lunatic—nobody knows quite what to make of Kapchuk. However improbably, the 46-year-old bon vivant is now the poster boy for one of many Kremlin efforts to lure back as much as $1 trillion of Russian cash stashed abroad. And like many good yarns involving Vladimir Putin, Kapchuk’s story starts with an unexpected visit from a presidential envoy—and a promise that seemed too good to be true. Back in February, Putin’s business ombudsman, Boris Titov, flew into London with an unusual offer for Kapchuk and a few dozen other wealthy Russians accused of financial crimes. At Pushkin House, a cultural center on Bloomsbury Square, Titov vowed to use the power of his office and an army of lawyers to help the men clear their names through Russian courts. All they had to do was come home. “You’d need to have your head examined to do that,” Ilya Yurov, a former banker, remembers thinking as he left the meeting. Like almost all of the attendees, Yurov received asylum in Britain precisely because Russia’s judiciary often functions as an arm of the Kremlin. (A U.K. judge in September rejected a request from Moscow to extradite Yurov.)

Well, Kapchuk, alone among Titov’s guests, bought the pitch. And his rationale for deciding to give up his cushy life to become a guinea pig in a quixotic experiment goes way beyond quashing charges related to the misappropriation of an apartment two decades ago. Shortly after the Pushkin House presentation, two events happened that changed Kapchuk’s thinking about Titov’s offer. The first was the nerve-agent attack on turncoat spy Sergei Skripal that Britain says two Russian agents carried out. Then, just days later, a former partner of the late fallen oligarch Boris Berezovsky, Nikolai Glushkov, was strangled in his home. Glushkov was No. 1 of 22 names on the London List, which quickly became Putin’s “hit list” in the British tabloids. Kapchuk, No. 12, said he found himself hounded by reporters who were sure his life was suddenly in danger. Admittedly paranoid, he agreed, but saw the threat coming from the other way. He said he read the attacks as a “provocation” by MI6 and hired two local bodyguards on the assumption that Britain would balk at endangering its own citizens in any attempt on his life. “I understood that a dead Russian is one thing, but if two U.K. citizens are also killed, that’s quite another matter,” Kapchuk said. The assertions dovetailed with Russian propaganda efforts, suggesting Kapchuk may have cut some sort of deal to get his case dropped, according to Gennady Gudkov, a former KGB and FSB officer who’s now an opposition politician. Kapchuk adamantly denies that, noting it took months for anyone in Moscow to respond to his pleas for help. Alone and with nowhere to turn, he said he jumped on a train to Paris and spent the next several weeks moving around Europe, sleeping in a different location each night. The plot thickened in May, when Kapchuk said he discovered Britain had annulled his travel permit—an unusual move if true. Legal experts say that’s normally only done with suspected terrorists. He said he learned this while traveling to a relative’s home in Croatia and border guards confiscated the permit without explanation, an account backed up by a Croatian Interior Ministry report dated May 7 and seen by Bloomberg. The ministry now says it impounded Sergi Windsor’s paperwork because it was declared lost, though it won’t say by whom. The U.K. Home Office declined to comment. It’s “odd,” said Christopher Cole, a U.K. solicitor who specializes in immigration issues. “It appears the U.K. government cancelled his travel document to stop him from traveling, but then wanted him to return.”