In the horrors of Auschwitz-Birkenau concentration camp during World War II, Saul Ausländer is a Hungarian-Jewish prisoner forced to assist the Nazis as a member of the Sonderkommando, the special group of Jewish prisoners isolated from the main camp and made to assist in the operation of the gas chambers and crematoria. Within this grim role, Saul discovers the body of a boy he takes for his son, who has survived the gas chamber only to be suffocated by a Nazi officer. Deeply affected and seeking some form of redemption amidst the brutality, Saul becomes fixated on the need to find a proper Jewish burial for the boy, rather than allow his body to be burned with the rest.

As Saul navigates the nightmarish landscape of the camp, his mission becomes increasingly desperate. He seeks a rabbi among the prisoners to recite the Kaddish and give the boy a traditional Jewish funeral, risking his life and the success of an uprising being planned by his fellow Sonderkommando members. Saul's single-minded intention to offer the boy a semblance of humanity in a place designed to strip it away brings him into conflict with other prisoners and his duties, while the clock ticks towards the inevitable confrontation between the prisoners and their Nazi captors. His singular pursuit stands as a silent rebellion against the inhumanity surrounding him.