In 1916, while England is deep in war with Germany, wealthy American Richard Bogard buys an estate in Kent and displaces its longtime occupant, Diana "Ann" Boyce-Smith. Although she has just learned that her father has been killed in action, Ann treats Bogard with brave graciousness and moves to the guest cottage without complaint. She then prepares to say goodbye to her brother Ronnie and childhood friend and neighbor, Claude Hope, both newly trained naval officers on their way to France. Before he leaves, however, Claude, who has loved Ann for years, proposes a postwar marriage, and she happily accepts. Soon after Claude and Ronnie's departure, Bogard accompanies Ann on a bicycle ride and tells her that he has enlisted in the Royal Air Force. Unaware of Ann's engagement to Claude, Bogard then confesses his love, and she finally admits that she, too, is in love. To Bogard's dismay, however, Ann leaves suddenly for a seaport in France, where she meets up with Claude and Ronnie and volunteers for the ambulance corps. Once alone with Ronnie, Ann confesses her love of Bogard, but although Ronnie advises her to tell Claude the truth, she insists on keeping her marriage pledge. Later, Ronnie shows Ann an official notice in which Bogard is listed as a casualty of a training accident. Ann quietly mourns for her dead lover, then assures a frightened, drunk Claude, who is about to leave on a particularly dangerous assignment, that she will "be there" for him when he returns. While Claude and Ann move in together with Ronnie's blessing, Bogard, who actually recovered from his accident injuries, returns to Kent and learns of Ann's general whereabouts. Bogard finally finds Ann in a military hospital, but after a brief, tearful reunion, she runs away without explanation. That night, Bogard and his flying companion, "Mac" McGinnis, come across a drunken Claude in the street and carry him to his home. Stunned to see Ann there, Bogard deposits the oblivious Claude and leaves in a disapproving, jealous huff. Bogard and Mac run into Claude again in a cafe and listen in disgust as he drunkenly tells them about the boat trips he takes with Ronnie. Convinced that Claude has an easy, safe assignment, Bogard invites him to fly his next mission, which involves bombing a German munitions works. Still unaware of Ann's connection to Bogard, Claude agrees to accompany Bogard and Mac and surprises them with his expert shooting and cool-under-fire bravery. When Ann learns of Bogard's actions, she tells Ronnie to invite Bogard on one of Claude's missions, hoping to change the American's lowly opinion of her. In the pouring rain, Claude, Ronnie and Bogard set out in a speedboat and, while zooming close to a German battleship, hand-launch a torpedo in a blaze of gunfire. Although the ship finally is sunk, Claude is blinded during the attack but, with Bogard, pretends that he can still see. After Bogard tells Ann that he at last understands her situation, Ann learns of Claude's blindness and says a final goodbye to Bogard. When Claude, who has deduced Ann's love of the American, hears that Bogard has volunteered for a suicidal bombing mission, he insists that he and Ronnie use their boat to destroy the targeted battleship. While the blind Claude mans the torpedo, Ronnie steers the boat directly into the German battleship, and both officers die in a spectacular explosion. Free to love, Ann and Bogard return to their home in Kent, where Claude and Ronnie are eulogized as heroes.