There’s no surer way to murder horror than to literalize it, a mistake incessantly made by The Moth Diaries. At a ritzy remote boarding school, Rebecca (Sarah Bolger), her BFF, Lucie (Sarah Gadon), and their nondescript friends sit around gossiping about virginity and excitedly pronouncing “This is going to be the best year ever!” Then the new girl, Ernessa (Lily Cole), arrives. A tall, gaunt specter, Ernessa’s weirdness immediately seems related to gothic-horror literature professor Mr. Davies (Scott Speedman) and his lectures about Dracula. Lacking the light touch and satiric black humor she deployed in American Psycho, writer/director Mary Harron has her characters verbalize their every emotion and hang-up—the central one being Rebecca and Ernessa’s shared experiences with suicidal fathers—while assigning Davies to telegraph the plot’s trajectory via his observation that vampire tales all feature sex, blood, and death. Lesbian desires, fears of mortality, and adolescent jealousies are all handled as bluntly as the unintentionally corny black-and-white flashbacks and gauzy dream sequences. With a round face marked by eyes set unusually far apart, Cole makes a reasonably haunting vision of sensual female malevolence, but not even her creepy lullaby that culminates with a bloody shower can counteract this girls-gone-crazy story’s mildness.