Unhappily married and uncomfortable with life among the British upper crust, Julia Sturges takes her two children and boards the Titanic for America. Her husband Richard also arranges passage on the doomed luxury liner in order to let him have custody of their two children. Their problems soon seem minor when the ship hits an iceberg.
Well-to-do Chicagoan, Larry Darrell, breaks off his engagement to Isabel and travels the world seeking enlightenment, eventually finding his guru India. Isabel marries Gray, and following the crash of 1929, is invited to live in Paris with her rich, social climbing, Uncle Elliot. During a sojurn there, Larry, having attained his goal, is reunited with Isabel. While slumming one night Larry, Isabel and company are shocked to discover Sophie, a friend from Chicago. Having lost her husband and child in a tragic accident, Sophie is living the low-life with the help of drugs and an abusive brute. Larry tries to rehabilitate her, but his efforts are sabotaged by Isabel who tries in vain to reignite Larry's interest in herself.
Detective Mark McPherson investigates the killing of Laura, found dead on her apartment floor before the movie starts. McPherson builds a mental picture of the dead girl from the suspects whom he interviews. He is helped by the striking painting of the late lamented Laura hanging on her apartment wall. But who would have wanted to kill a girl with whom every man she met seemed to fall in love? To make matters worse, McPherson finds himself falling under her spell too. Then one night, halfway through his investigations, something seriously bizarre happens to make him re-think the whole case.