Hunter appears to have a charmed life. Wide-eyed and bubbly, she spends her days homemaking and playing games on her cellphone. She was a retail worker who bagged a rich man. Bearing his child is just another privilege, like en suite bathrooms or the latest iPhone. Her pregnancy gifts her life with purpose. Still, she swallows a thumbtack well before her second trimester.

Determined to produce an heir, her domineering in-laws shuttle her off to therapy to uproot the compulsion. There, placidly smiling, she reveals a family trauma that disassembles any preconceived notions about the film’s relationship to gender, motherhood or even Hunter herself. She’s no twit, and her destructive behavior — inspired by that of Mirabella-Davis’s own grandmother, who was lobotomized for a hand-washing compulsion — becomes a savvy and tragic bid to retain her selfhood. What little independence she has as a wife can be distilled into the moments she steals to swallow objects, her private world as small as the tray on which she places a marble, an earring, a battery.

“The Lodge” and “Swallow” are so effectively disturbing because there are few Freudian terrors more primal than that of the mother figure who turns on her children, or the woman who violently rejects the very idea of maternity.

Grace and Hunter are not demons but martyrs, sacrificed to the feminine ideal of motherhood despite their independent desires. The disobedient mother is a horror trope because, as an idealized figure, she has so far to fall, and so many means by which to do so. In comedies like “Bad Moms,” unruly mothers use cursing and alcohol. In chillers like “The Lodge” and “Swallow,” they guzzle safety pins and play Russian roulette.