The Spy Who Came in from the Cold is a 1965 Cold War spy thriller film directed by Martin Ritt and starring Richard Burton, Claire Bloom, and Oskar Werner. The film is based on the 1963 novel of the same name by John le Carré.
Alec Leamas (Richard Burton) is a British spy who has been sent to East Berlin to discredit a high-ranking East German intelligence officer named Mundt (Oskar Werner). To do this, he poses as a disgruntled former spy who is willing to sell secrets to the East Germans.
As part of his cover, Leamas is fired from his job and left to fend for himself in East Berlin, where he begins a romantic relationship with a woman named Liz (Claire Bloom), who works at a library. However, things quickly become complicated when Leamas is arrested and sent to prison. He is eventually released and returned to London, where he is debriefed by his superiors.
Leamas is convinced that his mission has failed, but he soon discovers that Mundt has been arrested and charged with treason. As a result, Leamas is called to testify against Mundt in court. However, as the trial progresses, Leamas begins to realize that things are not what they seem and that he has been used as a pawn in a much larger game.
In the end, Leamas takes matters into his own hands and confronts Mundt, leading to a dramatic and fatal confrontation. The film ends with Leamas walking away from the courthouse, having successfully completed his mission and having come in from the cold.