July 1956. Álvaro Cunhal arrives at the Peniche Fort and is placed in the most modern and secure penitentiary wing, considered escape-proof. Despite the tight control exercised over the prisoners, Álvaro and his comrades manage to organize a small commune and provide support to the most vulnerable detainees, while looking for a way to escape. The prison’s security was tightened after the spectacular escape of Dias Lourenço, two years earlier, when the communist leader jumped from Segredo cell into the sea, in the middle of winter, swimming to freedom. Álvaro has six notebooks with him, where he records some of the harshest episodes of his life, such as the violent interrogation to which he was subjected in his first arrest, the insane days in solitary confinement or the death of his older brother. The routine in prison is difficult and repetitive. One day, one of his companions realizes that there is a vulnerability in the fort’s security, which they can use to escape. Inside and outside the prison, an escape plan is being prepared…