Construction engineer Bartley Alexander is a troubled, middle-aged man torn between Winifred, his American wife--a cold woman with clearly defined standards--and Hilda Burgoyne--an alluring mistress in London who has helped him recapture his youth and sense of freedom. Alexander's relationship with Hilda gnaws away at his sense of propriety and honor and eventually proves disastrous. (He is with Hilda when a messenger, unable to find him, fails to warn him that a bridge he is constructing is about to collapse.)