1961. Disgraced British spy, Fielding Scott, is given a chance to redeem himself in Berlin. He has to organise the defection of an East German scientist. Everything goes disastrously wrong.

Fielding's Berlin life is unraveling; he decides to "go rogue" and provoke the Russians into retaliating. At the same time he is now being blackmailed over his affair with Severine.

Fielding's clever plan seems to be working. The Russians are agitated, running scared. A date is mentioned for the first time - Sunday, August 13th. What will happen in Berlin on that day?

Fielding feels threatened and drops out of sight. Three urgent questions preoccupy him - the Beirut photograph; Severine's obsession with Udo Hoff; and the date - Sunday, August 13th.

Fielding, reeling from the death of Severine, knows he has more to do—he must avenge Severine's death. Fielding unmasks the traitor and all the Berlin mysteries are explained.