Four young Americans (Jonathan Tucker, Jena Malone, Shawn Ashmore, Laura Ramsey) decide to spend the last day of their Mexican vacation visiting an uncharted Mayan temple deep in the jungle. Big mistake—haven’t these kids seen Turistas or the Hostel movies? This time, in Scott B. Smith’s script (from his novel), the menace isn’t human, but something straight out of Little Shop of Horrors. It should by rights be a risible self-parody; Smith and director Carter Smith (no relation) avoid unwanted laughs only by resorting to relentless sadism. They let us know right off that nothing good will follow, and they carry it straight through to the abandon-all-hope-and-wait-for-the-sequel ending. It’s brutally efficient entertainment for those who enjoy seeing shallow, careless Americans get what’s coming to them.