IN 2012, Mark Duplass and Aubrey Plaza starred in Safety Not Guaranteed, a charmingly lo-fi genre-buster that, to great effect, merged time travel with a quirky romcom. Duplass treads similar territory in The One I Love, another hipster-Twilight Zone offering about attractive white folk confronting circumstances entirely beyond their understanding.

Duplass plays Ethan, a husband trying to regain the trust of his wife Sophie (Elisabeth Moss) after he cheated on her. Their shrink sends them to an idyllic weekend retreat, in hopes that booze, weed, and sexy solitude will allow Ethan and Sophie to reconnect with the best versions of themselves and each other.

But The One I Love makes that hope dangerously literal: Ethan and Sophie are baffled to discover that the guesthouse is inhabited by their exact dopplegangers—except Other Sophie and Other Ethan are funnier, sexier, and more relaxed. Ethan, desperate to reconnect with his wife, is suspicious of her pliable stand-in, but Sophie is susceptible to the charms of a kinder, cooler version of her husband.

Duplass and Moss ably juggle their dual roles, toggling convincingly between "real" Ethan and Sophie and their mysterious counterparts. Their relationship struggles feel authentic and true-to-life, and director Charlie McDowell is careful to present both sides of their relationship with equal care.

That evenhandedness gets him into trouble, though, with the film's supernatural elements—Ethan's sense of imminent danger is offset by Sophie's delight in her new paramour, murking up scenes that are meant to be suspenseful. More problematically, the film botches the central mystery of where, exactly, these dopplegangers came from, by providing exactly the wrong amount of information: It gives away too much for the audience to enjoy any open-ended sense of mysterious or metaphorical possibilities, yet too little to allow any satisfaction that the mystery has been satisfactorily solved. For all its potential, the result is off-kilter and frustrating.