Emily Young, a senior, wants to be elected as her sorority's president. She adopts a cute sloth, thinking it can become the new mascot and help her win, until a string of fatalities implicate the sloth as the main suspect in the murders.

A mother personally challenges the local authorities to solve her daughter's murder when they fail to catch the culprit.

In the 1930s, three friends witness a murder, are framed for it, and uncover one of the most outrageous plots in American history.

A detective investigates the death of the patriarch of an eccentric, combative family.

College student Ryan wakes up in his car on Tuesday, September 19. Returning to his dorm room, he walks in on his roommate Carter and Carter's girlfriend Tree. He resumes work on an experimental quantum reactor with fellow students Samar and Dre. After Bronson, the school dean, shuts down the project for triggering several power outages, Ryan is murdered by someone dressed as Babyface, and wakes up again on Tuesday the 19th. Tree explains her experience Happy Death Day#Plot, and she and Carter agree to help Ryan. They learn the reactor was responsible for creating the loop. The new Babyface tracks Ryan down, but Tree subdues and unmasks him to reveal another Ryan. The second Ryan warns that the original must die for the loop to close. Terrified, Ryan activates the reactor, releasing a powerful energy pulse that knocks everyone unconscious.