Two years after the events of the first film, Cole is now a junior in high school. He is unable to convince anyone except for his best friend Melanie that a satanic cult led by his former babysitter Bee really tried to kill him. However, Cole finds out his parents have applied him in a psychiatric school, and he escapes with Melanie alongside her new boyfriend Jimmy, and their friends Boom-Boom and Diego to join a lake party. At the party, Cole witnesses new student Phoebe, who has arrived at the lake after finding her missing childhood stuffed toy and directions to the lake in her locker. Later, Cole's friends play a party game on a boat when Melanie suddenly kills Boom-Boom. She then reveals to Cole that she believed him because she had joined the cult to achieve her dreams of becoming a famous influence, with Jimmy and Diego also revealed as cult members. With Boom-Boom's blood as a sacrifice, they need his blood again as an offering of an innocent to make their wishes come true. Original cultists Sonya, Allison, Max, and John also appear, having been resurrected so they could partake in the ritual or else they would die by sunrise. However, Phoebe suddenly appears, looking for gas for her jet ski, and provides Cole with some time to evade the cult members and escape with Phoebe on her jet ski. Once on land, Cole explains everything to Phoebe, who believes him, while the cultists give chase. Sonya is first to attempt to kill them, but they end up running her over with a car left by a stranger and is then decapitated with a surfboard after it flies off the car. Allison finds them, but the two trap her between a narrow wedge of rocks and then they proceed to rip her head off. The two board a boat and drive off, but Max catches the raft attached to the back of the boat and is able to pull himself onto the boat. However, Phoebe sets him on fire with a can of silly string and a lighter and Cole mutilates him with the boats propeller blades. Diego and Jimmy supernaturally disintegrate when they attempt to back off from their pursuit of Cole. Cole and Phoebe arrive at Phoebe's old family cabin, where they take refuge and hope to wait out the night, having been brought there from the mysterious message Phoebe received. In the cabin bunker, Phoebe reveals to Cole that her parents died because she crashed into them in a fatal car accident. Cole comforts her and admires her strength, and the two have sex. Melanie calls Cole's dad Archie, who has been frantically searching for him alongside Melanie's father Juan, and fakes being drunk so that he can pick them up, hoping to lure Cole out. Cole and Phoebe come out of the bunker armed with crossbows and John accidentally kills himself when a chandelier crashes on him. Cole and Phoebe flee and, after Archie follows after them, Melanie kills her father. Cole tells Phoebe to run away while he faces his father, who drugs him so he can take him home. Melanie and Phoebe face off in a fight, which ends with Melanie capturing Phoebe at knife-point so she can serve as bait. While stopping for gas, Cole regains consciousness, locks Archie out of the car, and drives back to the lake to save Phoebe. In a cove, Melanie holds Phoebe hostage before Cole shows up and volunteers to be sacrificed. Suddenly, Bee emerges out of the water and is revealed to be Phoebe's babysitter who was responsible for the car accident that killed her parents. It is then revealed in flashbacks that Bee made a deal with the devil so she could save Phoebe's life. Sonya, Allison, Max, and John are resurrected again, and the four alongside Melanie drink the blood of Cole mixed with Boom-Boom's blood. However, since Cole has had sex with Phoebe (thereby losing his innocence), the ritual backfires and the five melt and disintegrate. Bee, who did not drink the blood, reveals that she orchestrated everything so that Phoebe and Cole could unite and defeat the cult, having had a change of heart after Cole's love confession after her initial defeat. However, since Bee is still technically a demon, she drinks the blood and disintegrates to save the two. Archie shows up and, having witnessed Bee's death, now believes what Cole said was true. As the sun comes up, Cole and Phoebe embrace in a kiss. In a mid-credits scene, Bee's demon book is shown on the sand, still intact.