In Los Angeles, divorced editor Carol Hunnicut is on a blind date at a hotel restaurant with widowed lawyer Michael Tarlow, when a waiter delivers a message for him to phone a client. Tarlow goes to his suite to make the call and invites her to come with him.
While Hunnicut watches from a darkened room, the client, crime boss Leo Watts, unexpectedly arrives in person along with a gunman, Jack Wootton. Watts has learned that Tarlow stole from him and Wootton shoots Tarlow dead.
Having learnt that Tarlow was Watts’s lawyer, Hunnicut realizes that she is in danger. She delivers her son to his father and urges them to go into hiding, then flees to a borrowed cabin in the Canadian Rockies, telling only one person where she went and what she saw.
Police sergeant Benti traces Hunnicut and gives her location to deputy district attorney and a former Marine Robert Caulfield. Over the objections of his boss, Caulfield charters a helicopter flight to the cabin and meets a scared Hunnicut.
At this point, the group is attacked by Watts’ men, the pilot and Benti both being killed. Caulfield and Hunnicut escape in her SUV to a station, where a train to Vancouver is stopped. Caulfield must protect her from being mistaken for Hunnicut and killed.
Another passenger, Kathryn Weller, strikes up an acquaintance with Caulfield, who realizes he must protect her from being mistaken for Hunnicut and killed. As he rushes her to safety, another passenger, Keller, gets suspicious and reveals himself as a railroad policeman.
Caulfield fights off the two gunmen, before Weller appears, revealing herself as another assassin, but she is knocked off the train when it enters a tunnel. Later, in a Los Angeles courtroom, Hunnicut testifies about Tarlow’s murder and identifies Leo Watts.
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