Why did Bernard Samson's wife Fiona disappear into East Berlin, leaving him with two young children and a wrecked career as a spy? This, at last, is Fiona's story. We see how she was recruited by the KGB as a young Oxford student. We also see her rise through the hierarchy of the British intelligence system until she is their super spy for East Germany, her mission the dangerous dealings that will help bring down the Berlin Wall in 1989. Beautiful, brilliant Fiona is thus caught not only in the double world of two espionage systems but also in the growing realization that it is only through treachery and deceit of the ones she loves most that Fiona can serve her country.

Spy Sinker is the crescendo climax of the six previous best-selling novels by Len Deighton, and it ties them all together.