The Secret Screening at Fantastic Fest is always one of the most hotly anticipated events of the festival. Past years have brought guests such as Sandra Bullock and the Wachowski siblings to the Alamo Drafthouse Cinema. This year, with only one Secret Screening, guesses as to the surprise film screening ranged from big Oscar hopefuls such as “Birdman,” to high-profile genre films such as “Stretch.” However, no one predicted “Goodnight Mommy,” a deeply unsettling Austrian family drama with a pronounced mean streak.

The film begins innocuously enough, as twin brothers Lukas and Elias (Lukas and Elias Schwarz) enjoy a languid summer with their mother (Susanne Wuest), who is recovering from plastic surgery. She’s heavily bandaged and usually harsh towards the boys, refusing to even acknowledge Elias. As the summer goes on, the boys begin to question whether she’s their mother at all, a conflict that comes to a head in the disturbing finale. 

The Schwarz brothers are remarkable as the introverted twin brothers, giving a pair of completely natural, deeply intertwined performances. They’re an incredible find, and writers/directors Severin Fiala and Veronika Franz do a great job capturing the near-telepathic shorthand that builds between twin brothers. Meanwhile, Wuest gives a versatile performance, impressively brittle in the film’s opening stretch and agonizingly sympathetic in its finale.

“Goodnight Mommy” builds deliberately, becoming increasingly unsettling as the brothers wage psychological warfare on their mother. The film leaves a lot of questions unanswered by the end, but the most compelling is who is the worst influence on Lukas: his brother or his mother. Both function simultaneously as a devil and angel on his shoulder, which makes for a compelling viewing, anchored by a trio of fantastic performances.

As a Fantastic Fest film is supposed to do, “Goodnight Mommy” ends up in a very dark place, and the film’s uncompromising ending is pleasantly ambiguous. Although some questions are apparently answered, nothing is as it seems in Fiala’ and Franz’s discordant mental landscape. The result is a wholly unsettling film that disturbs just as often as it impresses.

Despite the many impressive elements of “Goodnight Mommy,” one wonders whether it’s a good fit for the Secret Screening slot. While Tim League, one of the Fantastic Fest co-founders, must be commended for programming the film, it almost certainly would have played better without the burden of expectation. Even so, “Goodnight Mommy” is right at home at Fantastic Fest and among the best, most memorable films of this year’s festival. It’s reportedly been picked up for U.S. distribution, so many more audiences can expect to see it soon.