Schoolteacher and family man Ed Avery, who's been suffering bouts of severe pain and even blackouts, is hospitalized with what's diagnosed as a rare inflammation of the arteries. Told by doctors that he probably has only months to live, Ed agrees to an experimental treatment: doses of the hormone cortisone. Ed makes a remarkable recovery, and returns home to his wife, Lou, and their son, Richie. He must keep taking cortisone tablets regularly to prevent a recurrence of his illness. But the "miracle" cure turns into its own nightmare as Ed starts to abuse the tablets, causing him to experience increasingly wild mood swings.