During the Spanish coup of July 1936, Nationalist forces occupy the city of Salamanca, leading to the arrest of its Socialist mayor. The respected writer Miguel de Unamuno, portrayed by Karra Elejalde, convenes with two colleagues—Protestant priest Atilano Coco Martin and the leftist Salvador Vila Hernández. They briefly discuss the coup before Unamuno departs for an interview where he expresses his support for the uprising. However, the discussion is abruptly interrupted when the mayor's wife approaches him, imploring him to advocate for her husband's release. Unamuno, unfortunately, offers only financial assistance, which is promptly rejected.
As the turmoil unfolds across the border in Spanish Morocco, a German delegation engages with General Francisco Franco in efforts to consolidate a singular Nationalist leadership following the death of General José Sanjurjo. Franco insists that the junta in Burgos retains authority despite increasing pressure from fellow leaders to take control.
Back in Salamanca, Unamuno faces repercussions for his public support of the coup when the government of the Second Spanish Republic removes him from his position as the rector of the University of Salamanca. Unamuno later meets with Coco and Salvador again, but the conversation escalates into a heated disagreement, resulting in Coco's departure. Afterward, Unamuno visits Coco's home, only to discover he is missing. Meanwhile, General José Millán-Astray arrives in Cáceres to consult with Franco, as the junta in Burgos reinstates Unamuno, who is then coerced into writing a manifesto endorsing the coup—an endeavor he adamantly refuses.
In his attempts to aid Coco, Unamuno learns from Coco's wife that he has been detained by the Nationalists. Salvador urges Unamuno to recognize the fascist nature of the coup. Meanwhile, Millán-Astray presses Franco to relieve the Siege of the Alcázar in Toledo, but Franco declines, noting the strategic ramifications such an action would incur. As tensions rise within the junta, Franco replaces the Republic's flag at his headquarters with the old monarchist flag, inciting unrest among his colleagues.
A critical meeting occurs in Salamanca where the junta and Franco convene, summoning Unamuno to plead for Coco's release. He is told that his case will undergo review, but soon faces Millán-Astray, who confronts him about his refusal to sign the manifesto. As the junta votes on leadership, with Millán-Astray advocating for Franco, Unamuno reluctantly signs the manifesto, only to find that Franco has been appointed commander-in-chief. Afterward, he encounters Coco's wife, who presents him with a letter asserting her husband’s innocence.
Inspired by an image of El Cid, Franco decides to relieve the siege of the Alcázar, garnering additional vigor for the Nationalist cause. In a subsequent meeting with Salvador, Unamuno engages in discussions regarding the ongoing war. However, their conversation takes a dark turn when Salvador is captured and arrested by Falangists, leaving Unamuno to return alone through the rain.
Following days of delirium, Unamuno seeks personal intervention from Franco and his wife to secure the release of his friends. This heartfelt attempt proves fruitless, causing him to share his sorrow with Coco's wife. In a climactic encounter, Millán-Astray informs Unamuno that he will represent Franco at a Nationalist event at the university the next day. Initially hesitant to speak at the event, Unamuno is compelled to deliver a powerful denunciation of the nationalists after reading Coco's wife's letter. This act incites the crowd's wrath, ultimately forcing him to flee.
The film concludes with an epilogue revealing the fates of various individuals entangled in this complex narrative.
