The unnamed protagonist is ordered to Helsinki by Dawlish, his boss, to suppress a newspaper article, potentially embarrassing to the U.K. government, about to be published by a Finnish journalist.

This woman, Signe Laine, is both romantically connected to and working for the protagonist's old American friend Harvey Newbegin (who also appeared in Funeral in Berlin).

Newbegin in turn attempts to recruit him into a private intelligence outfit, whose network is operated by 'The Brain', a billion dollar super-computer owned by eccentric Texan billionaire General Midwinter.

Midwinter is using his agency and private army to start an uprising in Latvia, at the time a part of the USSR, to end Communism in the Eastern bloc and tip the balance of the Cold War in favour of the West.

He infiltrates Midwinter's organization, braving unforgiving environments, violence and shifting loyalties, eventually to return to the Baltic to stop the virus from falling into the hands of the Soviets and the madman billionaire and protect British reputations in the process.