Dr. Caine, the murdering dentist from the original movie, has escaped from the mental hospital where he has been since being caught. Hoping to resume a normal life, he makes his way to a quiet Midwestern town under a false name and takes on the responsibilities of the town dentist Things are starting to look up for Caine, until the day when he catches his new love in the arms of someone else. Just as in the first movie, this sends him back over the edge and into another homicidal rampage, with his unfortunate patients bearing the brunt of his hostility.

Distraught when her middle-aged lover breaks a date with her, 21-year-old Toni Simmons attempts suicide. Impressed by her action, her lover, dentist Julian Winston reconsiders marrying Toni, but he worries about her insistence on honesty. Having fabricated a wife and three children, Julian readily accepts when his devoted nurse, Stephanie, who has secretly loved Julian for years, offers to act as his wife and demand a divorce.