Twenty years after the Spanish Civil War, Manuel Artiguez, a guerrilla fighter who has found sanctuary in the French town of Pau, receives word from Carlos, a smuggler, that his mother, Pilar, is dying in a San MartĂn hospital. Pilar learns that her son's bitter enemy, San MartĂn police chief Vinolas, with the aid of Carlos, has set a trap for Artiguez, and she persuades a local priest, Father Francisco, to carry a letter of warning to her son begging him not to come. Paco, an 11-year-old whose father was killed by Vinolas, destroys the letter, hoping that Artiguez will meet and kill Vinolas. When Paco sees Artiguez with the traitor Carlos, however, he tells Artiguez of his mother's death and the letter that he destroyed. Artiguez travels to Lourdes where Father Francisco confirms Paco's story, but he decides to follow Carlos to Spain anyway. Aided by Paco, Artiguez enters the San MartĂn hospital and manages to reach the roof, where he overpowers one of Vinolas' snipers and then kills Carlos. Artiguez is also killed in the gunfire, and Vinolas is left triumphant but wondering why the guerrilla chose to enter Spain and face his enemy.