Small town accountant Frank Bigelow went to San Francisco for a week of fun and then settled down with his fiancee Paula. After spending the night in the city, he woke up with more than a hangover; the doctor told him that he had been given a "glowing toxin" without an antidote and would only live for a week at most! Not knowing who did it or why, Bigelow began to take crazy risks to find his own killer.