Raising Cain (1992)

"I am what you made me, Dad."

Dr. Jenny O'Keefe seems to have it all. She has a successful career in medicine, a beautiful home, and a caring husband who has taken time off his own career as a psychiatrist to look after their young daughter. But her husband, Carter Nix, has been acting strangely lately. His attitude towards their daughter seems to have shifted from parental love into obsession, almost as if he's studying her, and he's been exhibiting swings in mood and personality. Perhaps that's why she is so quick to jump back into the arms of her former lover Jack Dante when he unexpectedly reappears in her life. And perhaps it's why she's been having these terrible nightmares.

In fact, things are much worse than Jenny imagines. Carter's tyrannical father, long thought dead, has come to town and brought with him Carter's identical twin brother Cain. Carter has found himself ensnared in his father's bizarre baby-kidnapping plans. Of course he's a good man at heart so there are boundaries he won't cross, but Cain has no such moral qualms. When the brothers find out about Jenny's affair with Jack, Cain comes up with a sadistic plan to take care of both of them in one go. And that's when things start to get really weird.