El presidio (1954)

After being fired from his company, Pablo meets his friend Ana, who introduce him to Pedro Ramírez, an undesirable lawyer, who offers him 15,000 pesetas for reports about his ex-company with the intention of doing a rob. When the lawyer's gang goes to give the coup, Ana reports them to the police, with the idea of taking the loot and fleeing with Pablo. But all of them are arrested and end up together in prison, where the intrigues and skirmishes between them will continue.