Nothing that happens in Coherence should be allowed to happen. The film begins with a comet that may or may not be infused with reality-altering powers screaming across the sky during a dinner party, causing a temporary blackout and potentially upending natural law. It would be a fool's errand to further summarize what happens in James Ward Byrkit's heady chamber drama, but imagine if My Dinner With Andre featured eight friends wondering if there are other versions of themselves in another house and, if so, which incarnations will still be there when this supposedly mystical comet disintegrates. Byrkit invokes everything from Schrödinger's cat to Gwyneth Paltrow, making Coherence feel like a puzzle whose pieces are constantly changing shape. The blurry, handheld cinematography is so up close and personal, and the house so small, that you feel the walls closing in just as surely as the characters do. The questions Byrkit raises about the intermingling of previously separate realities may be more inspired than some of the answers that his out-of-their-depth characters stumble upon, but the implications are quietly terrifying nonetheless: Every house is their house, and no house is their house. They have always been there, but they might never be able to return.

Critic's Grade: B

SEE IT: Coherence opens Friday at Living Room Theaters.