Narrow Margin

In Los Angeles, the editor of a publishing house Carol Hunnicut goes to a blind date with the lawyer Michael Tarlow, who has embezzled the powerful mobster Leo Watts. Carol accidentally witnesses the murder of Michel by Leo's hitman. The scared Carol sneaks out of Michael's room and hides in an isolated cabin in Canada. Meanwhile the Deputy District Attorney Robert Caulfield and Sgt. Dominick Benti discover that Carol is a witness of the murder and they report the information to Caulfield's chief Martin Larner and they head by helicopter to Canada to convince Carol to testify against Leo. However they are followed and the pilot and Benti are murdered by the Mafia. Caulfield and Carol flees and they take a train to Vancouver. Caulfield hides Carol in his cabin and he discloses that there are three hitman in the train trying to find Carol and kill her. But they do not know her and Caulfield does not know who might be the third killer from the Mafia and who has betrayed him in his office.