A retired British operative is discovered living and working at a very remote installation in Siberia, using a different name. Worried that he might have been a mole for Russia, the bossess at British Intelligence send John Purkiss to that area to learn more. Traveling there as a journalist, Purkiss witnesses deep-set tensions culminating in a murder and as the group tries to figure who and why, a group of Russian soldiers are sent there to eliminate everyone.