The latest Blumhouse shocker has a striking casting coup up its sleeve, but not a great deal else to recommend it. The perennially sweet Octavia Spencer has presumably bored herself silly playing kindly, matronly ladies in films like Hidden Figures, or even playing God in The Shack; as executive producer, she’s fashioned a horror role for herself that runs very much contrary to the image she’s cultivated until now. A group of teenagers have nowhere to go in a small town, until local vets assistant they call Ma offers them her basement as a place to hang out. Ma’s gift, complete with booze and snacks, comes at a price; she’s got an ulterior motive, and means nothing but harm. A remarkable supporting cast has been assembled, including Allison Janney, Luke Evans and Juliette Lewis, but they all take a back seat to Spencer’s Ma. Even when the action gets rather too sadistic for comfort, and there’s some nasty stuff here, Spencer relishes the task of taking her kindly features and seems to enjoy suggesting considerable malice lurking behind that familiar smile.