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.

Three magazine employees head out on an assignment to interview a guy who placed a classified advertisement seeking a companion for time travel.

Stuck in a time loop, two wedding guests develop a budding romance while living the same day over and over again.

Trapped in a time loop that constantly repeats the day of his murder, a former special forces agent must unlock the mystery behind his untimely demise.

At the age of 21, Tim discovers he can travel in time and change what happens and has happened in his own life. His decision to make his world a better place by getting a girlfriend turns out not to be as easy as you might think.