Stingo, an aspiring writer from the South, moves to Brooklyn in 1947, seeking inspiration for his novel. He rents a room in a boarding house where he meets Sophie, a Polish immigrant with a haunting past, and her mercurial lover, Nathan, whose volatile behavior oscillates between charm and cruelty. Stingo quickly forms a bond with the couple, drawn to Sophie's beauty and Nathan's intellect. As their friendship deepens, Stingo becomes aware of the deep psychological scars Sophie carries from her experiences during World War II, especially from her time in Auschwitz.

The narrative unfolds through a series of flashbacks revealing Sophie's harrowing memories, alongside her present struggle to navigate life with Nathan. Stingo learns about the impossible choices Sophie was forced to make in the concentration camp and the lasting impact these decisions have on her psyche. As tensions escalate between Sophie and Nathan, Stingo finds himself caught in their tumultuous relationship, attempting to provide support while grappling with his own feelings for Sophie. The weight of the past becomes increasingly impossible to escape as the emotional turmoil reaches a tragic crescendo.