As the story jumps back in time, we witness Mary, raised in a repressively religious household, finding fleeting happiness in the arms of Eleanor (Isabelle Fuhrman), the home’s maid.

Her family view the girls’ relationship as an abomination to be dealt with as severely as possible, with the tension only heightened by the arrival of an enigmatic intruder (Rory Culkin) and the revelation of greater forces at work.

The website's consensus reads: "Its restrained approach may frustrate horror fans seeking more visceral thrills, but The Last Thing Mary Saw tells a haunting period tale.

"[6] Dennis Harvey of Variety also gave the film a positive review, calling it "an arresting period piece", and noting that "Vitaletti merits admiration for a debut feature whose ambitions are off the usual beaten track.

"[8] Matt Donato of Paste Magazine gave the film a negative review and wrote that "The Last Thing Mary Saw feels restrained by its means — unable to emphasize its ultimate payoffs — and beholden to a tiptoe pace that won't ensnare all audiences.