Any movie that mixes the DNA of Mean Girls, Brick, and School Daze has my attention, and that’s pretty much what you get with Selah and the Spades, written and directed by Tayarisha Poe. Set at an elite boarding school, the movie follows the illicit dealings and interpersonal relationships among various student “factions.” Selah (Lovie Simone) runs the drug-dealing Spades with a ruthless grip, always suspicious of potential rivals. When she takes an underclassman (Celeste O’Connor) under her wing, it may not be for altruistic reasons. Simone and O’Connor are both strong and the movie has some striking flourishes. (Selah and her spirit squad’s direct-address routine about being a 17-year-old-girl—“We’ll tell you how short our skirts will be”—has an electric, School Daze vibe.) But unlike Daze and those other predecessors, Selah and the Spades never convincingly establishes its own stylized universe, resting somewhat uncomfortably between the real world and a fully realized, believably hermetic place.