While this horror-comedy from director Karyn Kusama has some truly scary moments, it’s often derailed by the script from Diablo Cody, who wrote Juno. Megan Fox stars as Jennifer, a high school cheerleader who becomes a demon after an ill-advised ride in an up-and-coming band’s van. Amanda Seyfried plays Needy, the nerdy best friend who witnesses her pal running around at night while covered with blood and flashing demon eyes. There are some sequences that work—I liked Jennifer’s first appearance as a demon, with her creepy, bloody smile—but Cody inserts all sorts of distracting wannabe catchphrases. Do girls really refer to each other as Vagisil or Monistat? Do high school kids call each other “Jello” or “Salty?” Each time one of the characters says something like this, the film feels dated. Too bad, because Fox and Seyfried are decent, and Kusama knows how to handle scares.