Shelly (late 30s) follows her sister, Thelma (late 30s), into an abandoned basement. She hasn’t seen her sister in years, but comes to visit her sister and brother-in-law for their wedding anniversary. Shelly thinks she’s going with her sister to decorate for a party, but once down in the basement, realizes her sister has more sinister plans. Thelma has her husband chained up in a bathtub and declares that she intends to boil her husband alive in it after years of abuse. Can Shelly talk her sister out of it or has Thelma finally reached the boiling point?