A mysterious hot tub repairman (Chevy Chase) appears and warns them not to change anything as it might affect the machine. In order to minimize the butterfly effect, the guys plan to re-enact their experiences. Adam has to break up with his girlfriend Jenny (Lyndsy Fonseca) and get stabbed in the eye with a fork; Lou must pick a fight and get beaten up by Blaine (Sebastian Stan), a ski patrol bully; and Nick must have sex with a groupie, and give a bad performance with his band at an open mic event. Jacob discovers his mother Kelly (Collette Wolfe) is at the resort but is acting rather slutty; he tries to figure out who is his father.