Tim Farnsworth is a well-regarded lawyer at a fancy, cutthroat midtown law firm in New York City, with a devoted, if occasionally uncertain, wife and a rebellious teenage daughter. Their comfortable marriage has survived her bout with cancer and his earlier bout with a strange condition: he will suddenly be compelled to walk, setting out on foot regardless of where he is or what he is doing, unable to stop himself until he eventually curls up asleep, whatever the weather and conditions around him. He is about to lead the defence of a prominent businessman charged in the slaying of his wife when the condition abruptly returns.