In Devil's Kettle, Minnesota, Needy Kesnicki is a shy teenage student that idolizes her cheerleader friend Jennifer Check, who is very arrogant. They attend a performance of the rock band Low Shoulder at a bar, and the band leader overhears that Jennifer is a virgin. When the place is set on fire, Jennifer is abducted by the band in their van. She later appears at Needy's home, covered in blood, throwing up a dark liquid and with a weird behavior. Over the next few days, many male classmates are found murdered with eaten parts of their bodies. Needy discovers that Jennifer was sacrificed by the band members in a black magic ritual, but something went wrong because Jennifer was not a virgin and she transformed into a flesh-eating succubus. Needy tries to keep her boyfriend Chip away from Jennifer.