Alec Leamas is the main character in John le Carré's novel, "The Spy Who Came in from the Cold." He is a British intelligence officer who becomes disillusioned with the espionage world during the Cold War. Leamas is tasked with a dangerous mission that involves deception and manipulation, reflecting the moral complexities of spy work. Throughout the story, Leamas grapples with themes of loyalty, betrayal, and the harsh realities of political conflict. His character serves as a representation of the struggles faced by individuals caught in the crossfire of East vs. West tensions during the Cold War.