In Stalinist Poland, cabaret singer Tonia decides to spend the evening drinking with a group of friends. The next morning, she awakes to find that, for reasons unknown to her, she has been jailed as a political prisoner. As prison officials interrogate, torture and humiliate her, she fights for survival and to maintain her innocence by refusing to sign a false confession. As her years of imprisonment pass, her relationship with her captors grows more complicated.