'Goodnight Mommy' has a sadistic streak

Beginning with a gentle lullaby and ending with a tightly packed wallop, "Goodnight Mommy" is one viscerally chilling, seriously unsettling horror film.

When their recently single mother (Susanne Wuest) returns from the hospital to their isolated rural home, her face and head swathed in scary bandages following an "accident," 9-year-old twin brothers Lukas and Elias (Lukas and Elias Schwarz) begin to have their suspicions. Outward appearance isn't the only thing about this less-than-maternal woman that seems to have changed.

Determined to uncover the truth, the boys, who prove to be no prize themselves, subject the woman to a series of increasingly sadistic punishments in order to extract a…