“Happy Death Day”
In “Happy Death Day,” Tree, a college student, is stuck in a time loop after a masked killer murders her on her birthday. In the end she learns it was her roommate Lori all along, and she stops her. But in the original ending, Tree kills Lori and sustains injuries. And while recovering in the hospital, the wife of the professor Tree was sleeping with murders her, making the alternate ending far more horrifying.