Brunete, summer 1937. In the assault on the Espolón hill, Javier de Montcada, a young man forced to participate in the civil war due to dramatic family circumstances, falls wounded in the battle of Brunete. The young soldier would have been riddled with bullets if Soledad , Duchess of Simancas, would not have donated her blood to him on the battlefield itself. After recovering from her injury in the military hospital in Salamanca, Soledad, married to the representative of the national side in the Vatican, seduces him in her pasture. Javier confesses his betrayal of his fiancée, Marie-Thérèse de Clermont, the young French woman whose family welcomed him and his mother after a tragic escape through the Pyrenees, in which his little brother was killed by the police. After learning that his father, a soldier who rebelled in Barcelona on July 18, had been shot, he swore revenge and enlisted in the Tercio de Montejurra. When he says goodbye to Soledad to return to the front, nothing makes Javier presage that the war still reserves a unpleasant news.