Lucca, 1942. After an act of desperate defiance, Margherita is committed to Maggiano by her husband. There she meets Mario Tobino, a doctor returning from the front who opposes the coercive methods of the institution. While rediscovering his old love Paola, now a partisan and persecuted, Mario seeks the truth about Margherita: is she really ill or just a victim of violence?
Margherita attempts suicide in isolation, but Tobino saves her. Meanwhile, Paola, a partisan courier, risks her life to reconnect with Mario. Meanwhile, in Maggiano, the psychiatrist promotes a creative workshop, encountering general skepticism. Determined to free Margherita, Mario investigates lawyer Lenzi.
Tobino saves Margherita from an attempted attack by Beppe. During the hearing before a judge to determine her mental insanity, Margherita confronts her husband, reporting his abuse, but is not believed: she breaks down, attacks him, and ends up in solitary confinement. Meanwhile, Paola tries to help Marta, a Jewish woman hiding in Maggiano.
The armistice raises hopes among doctors and staff, while hunger drives the patients to revolt. Director Roncoroni tries to obtain food supplies for his institution but fails. Paola, having escaped the roundups, visits Mario, and their meeting rekindles unresolved feelings as the Nazis storm the hospital.
Paola is in Maggiano to organize a masquerade ball to collect supplies and help Marta. Margherita, jealous of Paola, triggers a crisis that leads one of the patients to take an extreme step. Paola realizes Tobino's feelings while the doctor continues his investigation into Margherita. Beppe, now a member of the squad, breaks into the hospital.
At the masquerade ball, Nazi Colonel Sommer gives Roncoroni an ultimatum to hand over the hidden Jewess. In an apparently peaceful atmosphere, terror begins to spread among doctors and patients: everyone pays the price for their choices, while the fate of those who defied the regime changes forever.
