In Majorca during the Civil War, four children are witness to the execution of leftists by pro-Franco civilians. In a violent act of revenge, a boy whose father was among the victims kills the son of the leading executioner before committing suicide. Ten years later, the three surviving children are reunited in a sanitorium. The two boys have now become ill and the girl has now become a nun and is working at the sanitorium as a nurse. As time goes by both young men get progressively sicker causing one to become a fanatical religious zealot tormented by his love for the other, and the other in turn becomes more and more violent out of frustration. The nun who is in love with the two men can only watch as events build inexorably to the violent bloody finale.