Rosy Ryan is a young romantic girl living in the village of Kirrary, Ireland, during the Irish Revolution of 1916. She falls in love with the village schoolmaster, Charles Shaughnessy, a man who is twice her age. After a time, she tells him of her feelings, and he in turn admits his love for her. They are soon married, but the wedding night is an un-happy one for the two inhibited lovers. As Rosy grows increasingly discontent, she is chided by Father Collins, the local priest, who re-minds her that she should be satisfied with such a good life and husband.
Major Randolph Doryan, a young wounded British officer, takes command of the army occupation garrison near the village. While visiting the local pub, run by Tom Ryan, Rosy's father, the Major has a of shellshock. Rosy gives him comfort and is attracted to him. Soon they are lovers. The whole village becomes aware of this when one of Doryan's brass buttons is lost in a cave where the two have been together. Michael, the deformed village idiot, finds the button and parades up the street with it, imitating the Major.
Meanwhile, a Republican activist, Tim O'Leary, searches the area for a cove to beach a promised shipment of arms from Germany. In the height of a fierce storm, he enlists Ryan's help to salvage the endangered cargo. Ryan secretly informs the British. Resenting the British occupation forces, the whole village furtively goes to aid in bringing the cargo ashore. On returning from the beach, they are blocked by Doryan's British soldiers, who arrest O'Leary.
Though Ryan is the true informer, suspicion falls on Rosy because of her well-known relationship with the Major. Her husband, though ready to leave her because of her affair, comes to her side and is severely beaten when the villagers attack the schoolhouse. Seeking to punish Rosy as a traitor, the villagers strip her of her hair and clothing. Only Father Collin's arrival prevents further violence against her. Mean-while, Doryan has learned that Rosy has returned to her husband, When Michael shows Doryan the salvaged arms shipment that Michael has collected from the beach, Doryan waits until nightfall and then blows himself up. Learning of Doryan's death, Rosy and Charles decide to leave Kirrary.