This request sends a ripple of panic through the SIS, and Bernard Samson (a former field agent now working behind a London desk) is tasked with assisting in the escape.

A number of suspects are presented: Dicky Cruyer, his incompetent supervisor (whom Samson despises); Bret Rensselaer, an American who has built his entire career around the work of Brahms Four, and who had been spending an inordinate amount of time with Samson's wife, Fiona (also an intelligence officer); Frank Harrington, the 'rezident' (head) of the Berlin field unit; or any member of the senior staff at London Central, including the Director-General himself.

[2] Filmed on location in Berlin and Mexico, the project included a large international cast with 3,000 extras and a budget of $8 million.

In the preface to the reprint edition, Deighton notes that the novel is told in the highly subjective voice of the character of Bernard Samson, an unreliable narrator "who is inclined to complain and exaggerate so that we have to interpret the world around him".

The book's epigraph is a quote from James Jones: "readers should remember that the opinions expressed by the characters are not necessarily those of the author".