The Kremlin Device: Geordie Sharp, Book 3

This is the novel in which SAS Sergeant Geordie Sharp, always a loner and a maverick, finally goes over the edge. He is sent to Moscow to lead a team training the Russian Protection Service, a division of the former KGB, to acquire new anti-terrorist skills. The Russian Mafia is threatening to take control of the country, and Geordie learns, too, of their massive new presence in London.

The secret side of Geordie's mission is to plant a nuclear device in the sewers of Moscow as protection against any future Russian attack on the UK, a renewed danger in view of fast increasing political volatility and lawlessness. After two of his team are kidnapped, Geordie realizes that Mafia have control of the nuclear device, and he learns subsequently that it is being transported back to the UK.