Firewall — Andy McNab

If he hadn't needed the cash so badly, Nick Stone would never have messed with the Russian mafia. But the lucrative offer was one he couldn't refuse. The job seemed simple enough for a man of his particular talents: kidnap a ruthless, money-laundering mob boss from his fortified Helsinki hotel room and deliver him to St. Petersburg. But as the plan begins to unfold, Stone soon realizes that by no means has he been told the full story.

Catapulted into the bleak underworld of the former Soviet republic of Estonia, where unknown aggressors stalk the arctic landscape, Stone finds that the mob may now turn out to be the least of his problems. Russia has embarked on a new Cold War offensive -- hacking into the West's computer systems and stealing their most coveted military secrets. As one bloody double cross leads to another, Stone finds himself caught between the suicidal schemes of the British and American intelligence agencies and the ruthless Russians who want to silence him.