Based on Robert Sherwood’s autobiographical play, an American soldier who volunteered to fight for England in the Great War meets an American chorus girl living in London who picks up men to help pay her rent.
Myra Deauville (Mae Clarke) is dancing in a show and receives an animal fur as a gift. She and a friend go to likely places where they can pick men. At Waterloo Bridge during an air raid she meets Private Roy Cronin (Douglass Montgomery), and she invites him up to her cheap apartment where her landlady Mrs. Hobley (Ethel Griffies) reminds her she owes her rent money. Roy likes Myra and offers to give her money for her rent and for a new dress she wants, but Myra is ambivalent and gets angry at him after accepting it. He invites her to visit his family in the country with him, but she declines. After he leaves late at night, she goes out to the streets again.
In the morning Roy comes to visit Myra who is not there. The landlady says he can wait for Myra in her apartment. Myra’s neighbor Kitty comes in the window and talks with Roy until Myra comes in and sees the flowers he brought her. After he leaves, Myra gets angry at Kitty for telling Roy he should marry Myra and take care of her. Myra says she does not want to marry Roy.
After visiting his mother Mary Cronin Wetherby (Enid Bennett), his stepfather Major Fred Wetherby (Frederick Kerr) who is hard of hearing, and his sister Jane Cronin (Bette Davis), Roy goes back to London.
Roy goes to see Myra and persuades to go with him on a trip to the country, and without telling her takes her to his family’s estate. They persuade her to stay, and Jane says she can loan her clothes. Mary finds an opportunity to tell Myra that she believes she should not marry Roy. Myra says she does not want to marry him even she loves him.
The next morning Myra takes a train back to London. Roy goes to her apartment and tells he has to report back to the Army, and he begs her to marry him right away, and having paid her rent in advance, also gives her money. She asks him to wait outside while she changes and then leaves by the window. Roy discovers she is gone, and the landlady shows him the note Myra left, saying she could not do it. The landlady tells him that Myra is no good and makes her living picking up men.
Roy desperately searches for Myra and finds her on Waterloo Bridge. As a truck of soldiers are waiting for him to go with him, he pleads with her to marry him, and she finally agrees. Roy kisses her happily and gets on the truck. After the truck has gone, a bomb hits the bridge, killing Myra.