The IPCRESS File is Len Deighton's first spy novel, published in 1962. It was made into a film in 1965 produced by Harry Saltzman, directed by Sidney J. Furie and starring Michael Caine. The novel, which involves Cold War brainwashing, includes scenes in Lebanon and on an atoll for a United States atomic weapon test, as well as information about Joe One, the Soviet Union's first atomic bomb, although these elements did not appear in the film version.
The novel is framed as the unnamed protagonist delivering his personal report on "the IPCRESS affair" directly to the Minister of Defence, thus making the novel itself the 'IPCRESS File' of the title. The events begin soon after his transfer from military intelligence to WOOC(P), a small civilian intelligence agency reporting directly to the British Cabinet, where he works under the command of a man named Dalby. An intelligence broker code-named "Jay" is suspected to be behind a series of kidnappings of highly placed and influential British VIPs with the intention of selling them to the Soviets, and the protagonist is assigned to meet with Jay in order to secure the release of "Raven", a high-ranking scientist and his latest target. After meeting Jay at a sleazy Soho strip club to negotiate Raven's release, the protagonist is abandoned; investigating his surroundings, he discovers Raven's unconscious body in a back room and attempts to rescue him, but is unsuccessful.
WOOC(P) receives intelligence that Raven is to be transferred to the Soviets in Beirut, and a rescue mission is organised with Dalby and the protagonist participating. The protagonist is assigned as a lookout while Dalby kills Raven's captors and rescues him. The protagonist is forced to kill the occupants of a car which suddenly arrives on the scene in order to maintain the cover of the operation, believing them to be operatives working for Jay; they instead turn out to be members of ONI. The operation is otherwise a success and Raven is recovered, but the investigation into Jay continues. Dalby disappears, apparently going undercover, leaving the protagonist temporarily in charge of WOOC(P). At this point the protagonist's former superior from military intelligence, Colonel Ross, approaches the protagonist offering to sell him confidential information related to the affair. The protagonist rejects the offer in disgust, but begins to second-guess himself.