Demetrio Macías is a peaceful Indian who knows nothing about revolutions. When, as a follower of Francisco Indalécio Madero, he is hounded by the political leader of Jalisco, he flees with his wife and child to the mountains. There, federal soldiers come upon the fugitives at breakfast, and Demetrio runs off. He returns with a gun, however, to prevent the wild and lawless soldiers from raping his wife. Being no killer, Demetrio lets them go free, only to have them come back with reinforcements and burn his fields. Demetrio then joins a band of sixty sharpshooting rebel outlaws and helps them to drive off twice that many soldiers. During the fighting, two of the rebels are killed, and Demetrio is shot in the leg.
For two weeks, the outlaws remain hidden in a native village, looked after by Indians who hate the government. Venancio, a barber-surgeon, tends to Demetrio’s wound, and the village women use poultices of laurel and fresh pigeon blood to heal him. An attractive young woman named Camila is his nurse.
One day, the pseudointellectual Luis Cervantes blunders into the village and explains that he has deserted the government forces because his commanding officer assigned him to menial duty. Distrusting Cervantes’ glib tongue and big words, the rebels pretend to condemn him to death. One outlaw dresses in a priest’s robes and pretends to hear the deserter’s last confession to determine whether he is a spy. Accepted eventually as a revolutionist, Cervantes then urges the rebels to join the great revolutionary leaders of Mexico. Camila falls in love with him. Although she makes her feelings evident, Cervantes never encourages her, not even on the night of the outlaws’ departure. Camila has never responded to Demetrio’s lovemaking—Demetrio is only an Indian.
Hearing from messengers that Victoriano Huerta’s federales have fortified the city of Zacatecas, Cervantes urges the band to hurry to join the besiegers and take part in the capture. He flatters Demetrio by telling the Indian that he is more than a common rebel, that he is a tool of destiny to win back the rights of the people.
Demetrio plans a surprise attack on one of the towns along their march, but an Indian guide betrays the scheme, and the federales are prepared to resist. A friendly citizen shows the rebels a back way into the town, however, and the garrison is overwhelmed. The rebels find and stab the treacherous guard and kill the federal soldiers who survived the attack.
By the time General Natera arrives in the district, Demetrio’s reputation has grown so great that he is made a colonel in the revolutionary army. Failing to take Zacatecas, the rebels are forced to retreat, discarding their booty along the road. Demetrio thinks of going back to Camila, until news of General Pancho Villa’s coming excites the rebels and gives them fresh incentive.
During the next battle, Cervantes and Solis, an idealist, take refuge in a place where they think they will be safe. While they discuss the significance of the revolution, Solis is struck and killed by a stray bullet. Demetrio’s gallant charge turns the tide of battle for Villa and wins Demetrio promotion to the rank of general.
While drinking and boasting in a tavern after the battle, Demetrio meets Whitey Margarito, a vicious soldier, and La Pintada, a prostitute with whom Demetrio goes looking for a hotel room. Her insistence that, as a general, he should occupy a house of his own makes him decide to commandeer a fine residence.
During the ransacking, Cervantes finds a valuable diamond ring and the soldiers tear the pictures from books in the library. Whitey, joining Demetrio’s forces, runs off with Cervantes’ woman companion while Demetrio is arguing the matter of taking her instead of La Pintada, of whom he has tired.
Soon afterward, the rebels raid the house of Don Monico, Demetrio’s landowning enemy, and burn the estate. Cervantes, having collected much loot, suggests that he and Demetrio hide it in case they are forced to leave the country. Demetrio wishes to share it with the others. Still an idealist, he believes the rebel cause will triumph. Cervantes promises to get Camila for his leader, as Demetrio still wants her above all.
Cervantes goes to the village and persuades Camila to return with him. Believing that Cervantes is in love with her, she is surprised to find herself in Demetrio’s bed. The next morning, La Pintada discovers Camila and offers to help her escape. Camila refuses. She has found that she likes Demetrio, and she decides to stay with him and the rebel army.
During the march against General Orozco at Jalisco, Whitey shows his cruelty when he tortures a prisoner by tightening a rope around the man’s neck until his eyes bulge. Later, when kindhearted Camila persuades Demetrio to return ten bushels of confiscated corn to a starving villager, Whitey gives the man ten lashes instead. Camila’s protests at the incident win her the enmity of La Pintada, who has taken up with Whitey since Demetrio and Cervantes discarded her. When Demetrio, siding with Camila, orders La Pintada away from the camp, she becomes enraged and stabs Camila.
When Demetrio and his men reach Aguascalientes, they find Villa and Venustiano Carranza, once allies, fighting each other. The federal forces, taking advantage of the disunity among the rebel generals, defeat Villa at Celaya. The defeat is a terrible shock to Demetrio’s followers, who cannot bring themselves to believe that their idol has been beaten. The rebels are forced to retreat.
Cervantes escapes safely across the border. From El Paso, he writes to Venancio, the barber-surgeon, telling him that Whitey has shot himself. Cervantes invites Venancio to join him in Texas, where, with the barber’s money, they can open a restaurant.
After Villa’s defeat, Demetrio finds the villagers no longer willing to help the rebels. To them, he and his followers have become outlaws once more. Somewhat discouraged, he decides to return home. He has been away two years and has seen much, but he cannot answer his wife’s questions when she asks him why he kept on fighting. He lacks Cervantes’ glib tongue to put his true feelings into words.
Trying to pacify the landowners of the region, the government sends troops into the uplands after the outlaw band. Once more the rebels and the federal troops clash. Outnumbered, the outlaws perish on the spot where two years before they had won their first victory. After the fighting has ended, the soldiers find the body of Demetrio Macías, his dead eyes still sighted along the barrel of his gun.