Donald Sinden portrays a very different kind of character role -- a cold-blooded killer -- in this taut British thriller. One night, Jay and Lucy, a young married couple quarrel and Lucy leaves to go to the cinema on her own. During the film, her anger cools but, as she leaves to return home, she unwittingly becomes a witness to a murder. The killers see her and chase her until she runs into the path of a bus and is critically injured. The two criminals wait to hear of her condition, but as she improves, one of them strikes on a plan to kill her.