Max Cartwright waits while her actress mother, Amanda, auditions for a film. The film features Dakota Payne in the role of The Driver. When Amanda returns, she vents that she will always be known as the scream queen Nancy of the 1986 slasher Camp Bloodbath, a cult classic. On the way home, the two are involved in a car accident and Amanda is killed.
Three years later, on the anniversary of her mother’s death, Max is studying with her friends Gertie and Chris. Gertie’s stepbrother Duncan, a horror film fanatic, persuades Max to attend a special double feature showing of Camp Bloodbath 1 and 2. At the screening, Max encounters Vicki, Chris’s possessive ex-girlfriend and her former best friend. During the film, the theater is accidentally set ablaze. To reach safety, Max slices a hole in the screen and the group steps through.
Max, Chris, Gertie, Duncan, and Vicki awaken in the woods. They encounter a van filled with Camp Bloodbath characters asking for directions to the camp. The van leaves and returns every 92 minutes, and the group realizes they are trapped in a time loop, transported into the movie world. When the van returns again, they pose as new camp counselors and hitch a ride to camp. The movie’s machete-wielding killer, Billy Murphy, spots them but initially just stares. Duncan tries to snap a selfie with Billy, only to be stabbed, dispelling any hope that they will be spared for not being real movie characters.
The group tries to keep the onscreen couple from having sex, since Billy appears whenever that happens. Chris distracts Kurt, while Max convinces Nancy to remain a virgin. Vicki sticks with Paula, the Final Girl, and Gertie bonds with Blake. As Gertie mentions Billy, the counselors realize the urban legend is real and that the killer will come for them. In a panic, they flee. Kurt and Paula drive off, but Duncan reappears alive; the car crashes into a totem pole, killing all three.
Now aware that the survivors who originally lived can die, Max and the others resolve to save anyone they can. They dress Tina in a life jacket and mittens to keep her more modest, and they decide that Max, the last remaining virgin, will be the new Final Girl, plotting to place Billy’s machete in her hands so she can kill him and end the film. Meanwhile, Max and Nancy bond and theorize that if Nancy survives, she could return home with Max and be whoever she wants.
The group booby-traps the cabin, then Tina lures Billy with a striptease. Tina panics as Billy closes in and is killed when a trip wire sends her headfirst into a bear trap. Blake, Vicki, and Gertie also fall in battle against Billy. Chris, Nancy, and Max flee, and Billy pursues. They attempt to escape via a flashback, but Chris is stabbed, and Billy kidnaps Nancy. Max finds Nancy at Billy’s barn hideout, and the two women fight Billy, with Max getting stabbed before they both escape.
They retreat to the chapel, where Max tells Nancy that in the real world she is Max’s mother. Nancy realizes that for Max to become the true Final Girl, she must sacrifice herself, and the two share a tearful farewell before Nancy lures Billy with a striptease and is killed. Max collapses, but now the Final Girl, she rises with the power to kill Billy. They fight and she decapitates him with his own machete. A wounded Chris arrives and the two share a kiss as Camp Bloodbath’s credits shimmer in the sky.
Max wakes in the hospital, reunited with her friends. They hear Billy Murphy’s approach tune and realize they are within Camp Bloodbath 2: Cruel Summer. Billy crashes through the hospital’s glass doors as the title appears, and Max lunges at him.
