The story starts on a night in New York, when while strolling in the park, Michael O’Hara meets Mrs. Bannister and talks for a little bit with her. After they depart, Lady Bannister gets attacked but is saved by Michael who then accompanies her to her car.
While they are walking, Michael tells Mrs. Bannister that he is a sailor which offers her the chance to ask him to work for her on her yacht. Michael refuses after he finds that she is married but Mrs. Bannister asks him to think about it.
The next day, Mr. Bannister comes to ask Michael to work for him bur he refuses once again. They go out for a couple of drinks with another two men and Mr. Bannister gets so drunk that he has to be taken home by Michael. There, he meets Mrs. Bannister once again and this time, he agrees to work for them and accompany them.
On route, they meet with one of Mr. Bannister’s associates, Grisby. Grisby had found about Michael’s past, about how he killed a man and asks him that if he would do it again if he would have the chance. Michael doesn’t respond so Grisby leaves.
When Mrs. Bannister, Rosalie, returns from swimming, she makes it clear that she attracted to Michael but he refuses her, an action which shocks both her and him. Michael tells Mr. Bannister that he wants to quit but Rosalie convinces him not to do it.
Grisby approaches Michael again and tells him that he wants to fake his own death. He asks Michael to help him and promises him 5.000 dollars, money which Michael intends to use to run away with Rosalie. Grisby promises him that he will not be convicted as long as there is nobody and puts Michael to sign a confession.
On the day when the supposed crime was to take place, Sydney Broome a private investigator hired by Bannister, meets with Grisby and tells him that he has found of his plan to murder Bannister, run away and blame Michael for both murders. Grisby shoots Sydney and then meets with Michael who proceeds with the plan, unaware of what happened.
Sydney calls Rosalie and tells her about Grisby’s plans. When Michael also finds out what has happened, he rushes to Mr. Bannister’s office but instead of finding Mr. Bannister dead, Grisby is the one who was killed.
Michael is accused of Grisby’s murder and locked away but Mr. Bannister promises him that he will represent him in court. During the trial, Mr. Bannister finds that Rosalie started liking Michael and predicts that he will lose the case. Before the verdict is given, Michael escaped by pretending to kill himself and then meets with Rosalie at a theatre. There, he realizes that it was she who wanted her husband dead but it is too late to run and he is captured by Rosalie’s Chinese friends who take him to an abandoned building. There, he finds that Rosalie plotted with Grisby to kill Mr. Bannister but because Sydney appeared, she had to kill Grisby in order to save herself.
The movie ends in a hall of mirrors, where both Rosalie and Bannister die and Michael is left with the hope that what he has found will let him win the trial.