A dentist finds himself a murder suspect after a sexy patient seduces him into prescribing her drugs.

Nathan Caine was born with the rare disorder CIPA (Congenital Insensitivity to Pain), which means he does not feel physical pain. He grew up a sheltered child, learning to blend his food so he would not unwittingly chew off his own tongue, and he learned to wear a timer to remind himself when to go to the bathroom. But when his bank is robbed and his new love taken hostage, his affliction becomes his greatest strength as he sets out to rescue her.

An industrial worker struggles to pacify his worsening toothache.

Dr. Feinstone escapes from the mental hospital where he has been held ever since his wife's adultery sent him on a deranged killing spree. Hoping to resume a normal life, he makes his way to a quiet Midwestern town and establishes himself in a new practice under an assumed name. Things are starting to look up for Dr. 'Caine' – that is, until the day he catches his new love in the arms of someone else. As before, the impact of romantic betrayal sends him over the edge into madness and murder, with his unfortunate patients once again bearing the brunt of his hostility.