Head of Russia desk in British Intelligence, John Henderson, is convinced the Russians have launched Operation Overture, a deadly cold war-era plan to plunge the West into chaos. That somewhere on British soil is a Russian sleeper receiving the Soviet Union's missing suitcase nuclear bombs in preparation for a series of devastating attacks across the vulnerable continent.

But his cries fall on deaf ears. To his superiors Henderson is a fantasist and Overture his fantasy. More pressing is uncovering the high-ranking mole Moscow Centre placed inside MI6 years before.

Now the clock is ticking on a seemingly impossible international manhunt to prevent the elusive assassin from wreaking his murderous destruction.

It's man against man, East against West, just like the old days...
The trouble is this time is it's unclear where each man's loyalties truly lie...