In the midst of the Cold War, a cunning British secret agent, Harry Palmer, is recruited by the government to investigate a series of mysterious disappearances of key scientists. However, unlike other spies of the time, Harry is not the typical action hero: he is a former soldier stuck in an office job with a sarcastic personality, who prefers everyday life and curry rice to the life of espionage.
As he unravels the case, he encounters a labyrinth of deceit and manipulation, where nothing is as it seems. As he delves deeper into the world of espionage, Harry uncovers a secret operation aimed at erasing the memories of scientists, all through a sinister method called "the Ipcress file." At the same time, he faces pressure from the intelligence service that is keeping a close watch on him, as well as his own personal demons.
Interspersed throughout the plot are intriguing twists, a constant game of cat and mouse between Harry and his adversaries, along with a healthy dose of black humor. With a visual style that defines the era and a unique soundtrack, the film becomes a reflection of Cold War paranoia. As Harry navigates this dangerous intelligence game, he realizes that his loyalty is at stake and that sometimes the truth can be more dangerous than the lie itself.