It's 1991, two years since the fall of the Berlin Wall, the day before the start of the failed coup to topple Gorbachev in what's left of the Soviet Union.

Canadian Intelligence agent (and television actor) Evan Harris has been asked to reopen an investigation on Victor Barnfather, a senior MI5 official long suspected of having ties to the Soviets. Evan, who once played a spy on a cult television series in the 1960's, enlists the help of his eldest son, Canadian Intelligence agent Ian Harris, and an old friend, spy novelist Emma Braden. A diversion is planned which involves the London Underground, and for this Evan turns to his middle son, Anthony, a West End actor.

Also crucial to the plot is Romilly Square, an abandoned tube station whose surface building is presently occupied by a travel agency. Evan's youngest son, Robin, is recruited to help with the investigation when it becomes known that Robin has had a previous relationship with one of the travel agents, Sara Woodford.

The climax takes place beneath the travel agency, on the old Romilly Square platforms, in a scene which pays homage to tv spy shows from the 1960's.