In New England, a formal wedding is interrupted by the arrival of an uninvited guest. Within seconds, several people lie dead. In Brittany, a funeral is attended by a man who is neither welcome nor expected, and soon there are more to bury than the corpse in the coffin. Tom Bullen has worked for the intelligence service before; he was useful to them during the Cold War as a low-level courier. Now there's a more personal reason for his being involved: his mother's brother - a politician and a neo-Nazi sympathizer - was among the dead at the French funeral. Bullen is a tough-minded and difficult man - afflicted by the past, uncomfortable with his long-standing relationship with journalist Anne Warbeck, at loggerheads with himself. Trading off his restlessness and liking for risk, Bullen's former bosses persuade him to find out what he can. An experienced caver, Bullen knows that sometimes there's only one way to go - further and deeper. The trail leads Bullen to Sonia Bishop, a woman who knows too much, and whose knowledge could prove lethal. Amid the bayous of Louisiana, Bullen uncovers a conspiracy to barter the world's most terrifying weapons. He goes up against arms dealer Axel Dexter and unwittingly leaves Sonia vulnerable to one of Dexter's hired hands, a man whose pain and madness, like a terrible stain, mark those he loves and those he hates. Finally, Bullen comes to the dark heart of the conspiracy in Moscow, a city that seems to be throwing the last party before the end of the world. Here he uncovers the deepest and most fundamental betrayal as the conspirators cold-bloodedly trade doomsday for dollars.