It’s rare for a movie to establish a tone that lies outside familiar genre boundaries, yet this strange and endearing combination of horror, comedy and filmmaking satire manages just that. The low-budget experiment, written and directed by brothers Jay and Mark Duplass, follows four no-budget filmmakers who hole up in a cabin in the woods. They plan to make a horror film about a man wearing a bag over his head who terrorizes two couples on a weekend getaway. Midway through the filming of their misguided project, a real “baghead” begins banging on the windows – or is it one of the four trying to juice up the creative process? Uncertainty, not to mention a few moments of real terror, take over, right through to the jarring end.