The story would be fit for a spy novel if it weren't so implausible. A Russian ex- KGB agent turns against the Kremlin and flees Moscow. He continues his attacks from exile in London, until he is poisoned with a rare radioactive isotope and dies a slow painful death.
As correspondent Bob Simon reports, this is the real life story of Alexander Litvinenko, the first-ever victim nuclear terrorism.
Two weeks after he was poisoned, Litvinenko no longer looked like the healthy man he once was – he looked like an ordinary man in his death throes.
Friends of Litvinenko paint him as a martyr, murdered to silence his criticism of Russia's president, Vladimir Putin. But a darker picture emerged from interviews 60 Minutes did with people who knew him, a portrait of a desperate man fighting for attention and for money, by dealing in the only commodity he knew: information, secrets.
Marina Litvinenko, his widow, was with him the evening he first felt ill. They were preparing to celebrate their anniversary and the fact that they had just become British citizens.
Asked what the first sign was that something was wrong, Marina Litvinenko tells Simon, "Just noticed it just before midnight, after eleven. It started just like a simple sickness. He told me 'Marina, I feel like, quite, not good.'"
She thought he was just sick but says this was unusual, since her husband never got sick.
Litvinenko kept himself in good shape. But just days after those first signs of illness, he was hospitalized. At first, doctors thought he had an intestinal problem, a virus. But by the second week in the hospital, Marina Litvinenko knew something very strange was going on with her husband, who she calls "Sasha."
"Sasha started to feel very bad," she remembers. "His skin became very yellow. When I arrived on Monday, he couldn't open his mouth at all. It was so scary."
And it got worse. Litvinenko's hair fell out in clumps. Doctors realized he had been poisoned, but weren't sure by what. They didn't have a clue. All Scotland Yard could do was seal off his room and try to protect him.
But it was too late. The poison was eating him away from the inside. Police believe it had been administered sometime during the day of Nov. 1, a day on which when he met at least four people.
One was Mario Scaramella, a self-styled Italian investigator who he met at a sushi bar in central London. Scaramella told 60 Minutes he warned Litvinenko that both of them were on a Kremlin hit-list. Litvinenko had sushi, Scaramella ate nothing. Scaramella is now in jail in Italy on unrelated charges.
After lunch, Litvinenko came to a hotel in London's posh Mayfair district, where he met three Russians, all former security agents, to discuss what Litvinenko described as "a business proposition."
One source told 60 Minutes they talked about gathering information on prominent Russians, information they would sell to western investors considering doing business in Russia. They met in the hotel bar but Litvinenko didn't drink; he only had a cup of tea. But authorities say that was one cup too many. They believe the fatal dose of poison was slipped into his teacup.
That was November 1. In the evening, three weeks later, Marina prepared to leave the hospital.
"Then I told him, 'Sasha, I have to go home. And he told me, 'Marina, I love you so much.' And I just say, 'Oh, Sasha. I didn't hear it so long time. I'm very happy you tell me again.' It was his last word to me," she remembers. "It was like saying goodbye to me."
Litvinenko died the next night. It was only then that doctors determined what precisely had killed him: a little known radioactive isotope called polonium 210. Tasteless, odorless and lethal, a tiny speck is all it takes to kill. Traces of the polonium were found at the sushi bar, the hotel, and a trail of other places and people – from jetliners to a soccer stadium, from barmen to cops to Marina Litvenenko. So far, 14 people have shown signs of contamination.