In World War I London, Myra is an American out-of-work chorus girl making ends meet by picking up men on Waterloo Bridge. During a Zeppelin air raid she meets Roy, a naive young American who enlisted in the Canadian army. After they fall for each other, Roy tricks Myra into visiting his family, who live in a country estate outside London, his mother having remarried to a retired British Major. Myra is reluctant to continue the relationship with Roy, he not aware of her past.