Two semi-estranged sisters and their mates spend an uncomfortable country weekend together in “The Sleepwalker,” a consistently intriguing psychodrama that may nonetheless leave many viewers feeling that it’s all buildup and scant payoff. Commercial prospects look iffy for helmer/co-writer Mona Fastvold’s debut feature, which gestures toward thriller and explosive-family-secrets terrain without ever quite committing to either.
Kaia (Gitte Witt) and Andrew (Christopher Abbott) are introduced as an affectionate couple of recent vintage busy renovating the large rural Massachusetts house she grew up in. Her father was its architect, and before his death he hired Andrew — another local kid, of scruffier background and rougher demeanor — as a laborer/apprentice.
In the middle of the night, there’s a call from Kaia’s sister Christine (Stephanie Ellis), who on impulse has traveled up there and now wants to be picked up at the train station. It’s a tense reunion — apparently Chris was responsible for some past events Kaia is not yet ready to forgive — partly smoothed over by the visitor’s news that she is pregnant, and engaged to previously unmentioned Ira (co-scenarist Brady Corbet). A Boston rich kid-turned-U.N. human-rights inspector, Ira shows up the next morning rather ruffled (not for the first time) by Chris having left without a word.
The visitors more or less invite themselves to stay on; Ira tells Kaia that since the frequently troubled Chris is off her meds for the baby’s sake, a sister’s stabilizing influence would be welcome. But things remain awkward, with the slightly condescending Ira and resentful, quick-to-anger Andrew taking an ill-concealed instant dislike to each other. Then there’s Chris’ lifelong habit of sleepwalking, which proves alarming when she’s found performing an intimate act while standing over her unconscious hosts’ bed.
One morning she’s nowhere to be found, distressing her husband-to-be and sibling more with each passing hour while Andrew’s patience wears dangerously thin. The key to a family history that the sisters remember quite differently is Kaia’s permanent disfigurement from a long-ago garage fire; its cause is revealed (if not explained) in a final sequence that’s effective as far as it goes, but feels undernourished as the narrative endpoint.
Performances are strong, with Abbott especially good as a man who truly loves Kaia, but proves very poorly equipped to adapt when the needs of others complicate their self-contained universe of two. Polished assembly is highlighted by Zachary Galler’s atmospheric widescreen lensing; an offbeat score from Sondre Lerche and Kato Adland that renders ominous scenes otherwise innocuous; and the distinctive house location itself, a 1920s modernist brick structure at once plain and arresting.