Beginning as a more earnest Night of the Comet before swiftly morphing into an episode of the Twilight Zone without sacrificing its you-are-there vérité, Coherence is a low-budget chamber drama that firmly puts the psychological screws to its characters. It gathers four couples at a dinner party the same evening a comet passes Earth, an occurrence that promptly severs cellular communications and cuts electricity. But when the group realizes that a house down the street still possesses power, Hugh (Hugo Armstrong) and Amir (Alex Manugian), adhering to standard scary-movie convention, go sleuthing. Once they return, however, the narrative, which had been building slowly into a haunted-house attraction, with menacing noises at the door and ominous stories about Siberia’s Tunguska Event of 1908, realigns and turns diabolically quizzical, reimagining Mike Cahill’s Another Earth as a taut parlor game of possible parallel lives.
That duality is made plausible through brief recitations from a thick textbook on the finer points of quantum mechanics and a layman’s explanation of Schrödinger’s cat. If that sounds unbearably erudite, writer-director James Ward Byrkit offsets the headiness with drollness, such as a reference to the 1998 Gwyneth Paltrow rom-com Sliding Doors. He makes metaphysics, rather than scientific cogency, the film’s foundation, content to use Edwin Schrödinger’s thought experiment as an engine to explore the alternate self, how every decision is a stepping stone to the here and now. And in spite of the gimmicky concept, the film remains emotionally acute, all the actors convincing as genuine friends prone to bouts of passive aggression, credibly reacting to the frenzied twists the story takes. Not everyone is who they seem, but this impression of personas is much less traditionally sinister than representative of the film’s inquiry into identity and what happens when social barriers begin to fall away.
Though Coherence is an ensemble, its third act tellingly shifts its focus to Emily (Emily Foxler), a one-time ballerina who, when she was presented with the opportunity to understudy for a famous dancer, impetuously declined, only to watch her replacement ascend into the limelight instead, a life misstep that’s essentially paralyzed her. “To the lives we lead,” says Hugo, attempting to assuage her regret. It’s a line that underscores the film’s exploration of paths people lay out for themselves. The comet becomes the cosmic propellant by which Emily’s made to question the life she leads, and while the conclusion appears open-ended, it’s actually a thunderous answer, as she comes face to face with herself and realizes she has no idea who she is.