| Director | Matt Bettinelli-Olpin, Tyler Gillett |
|---|---|
| Genre | black comedy film, horror film, thriller film |
| Runtime | 95 min |
| Country | United States |
| Budget | $6 million |
| Box office | $57.6 million |
As a child, Daniel Le Domas is confronted in his family's mansion by Charles, a wounded man who begs him for help. Instead, Daniel alerts his family, who arrive in ceremonial masks and robes. Despite his bride Helene's pleas, Charles is shot with a speargun and dragged away into a locked room.
Thirty years later, Daniel's brother, Alex, the estranged son of the owners of the successful Le Domas Family Games company, is set to marry Grace MacCaullay, a former foster child. On Alex and Grace's wedding night, she meets the Le Domases: Daniel and his wife Charity; Alex's cocaine-addicted sister Emilie, her husband Fitch, and their young sons Georgie and Gabe; Alex's Aunt Helene, and his parents Tony and Becky. Before the game, Tony explains that his great-grandfather Victor Le Domas made a deal with someone named "Le Bail" to build the Le Domas fortune in exchange for the family observing a tradition: at midnight on their wedding day every new member draws a game card from Le Bail's puzzle box. Grace draws "Hide-and-Seek". Believing it to be a harmless game, Grace hides herself as the Le Domases each receive a weapon. Alex finds Grace, who witnesses Emilie accidentally kill a maid whom she mistakes for Grace.
Alex reveals that his family is cursed: if the new member draws the Hide-and-Seek card, the rest must find and ritually sacrifice them before dawn, or they die instead. The card was last drawn by Helene's husband, Charles, who was then found and murdered. With the mansion locked down, Alex disables the security system to allow Grace to escape. She is discovered by Daniel, who is disillusioned with his family, and gives her a head start before alerting the others; Emilie accidentally kills another maid in the chaos. Grace's escape is blocked by the family butler Stevens. She, in turn, splatters boiling tea onto his face and runs away. Daniel and Tony restrain Alex after he attacks the latter. Grace is seen by a third maid who accidentally crushes herself in a dumbwaiter while alerting the family to Grace's presence.
Grace runs to the goat shed, where Georgie shoots her in the hand. She knocks him out but is startled by a goat and falls into a pit filled with the remains of the Le Domases' previous sacrifices, including that of Charles. She escapes, makes it through the front gate, but is captured by Stevens. As he is driving her back to the house, she awakens and attacks him, causing the car to crash and kill him. Near the crash, Daniel detains Grace after realizing that his father is watching.
The Le Domases prepare to complete the ritual sacrifice. However, they are incapacitated as Daniel had poisoned them with a non-lethal dose of hydrochloric acid in the ritual cup. Charity shoots Daniel in the neck, leaving him to bleed to death as Grace runs away. In the ongoing chaos, the mansion is set ablaze, and Grace is attacked by Charity, who she knocks out with her empty gun.
Alex escapes his restraints to find Grace killed his mother Becky with Le Bail's box. Grace pulls away from Alex, who, realizing that she will never trust him and will leave him once she escapes, subdues her to complete the ritual. Grace breaks free just as the sun rises. At first, nothing happens, convincing the family that Le Bail is nothing but a myth. However, Helene still decides to kill Grace, believing it will please Le Bail. But as soon as Helene attempts to kill her with an axe, she explodes into pieces, revealing the curse to actually be true. The remaining members of the family explode one by one, leaving only Alex, who tries to convince Grace to forgive him. She refuses and tosses her ring back, declaring she wants a divorce; Alex then succumbs to the curse and explodes. Le Bail briefly shows himself to Grace and nods at her.
The sole survivor of the night, a blood-covered Grace, walks out of the burning manor just as the police arrive. She sits down in front of the burning building for a smoke; when asked what has happened to her, she simply replies, "In-laws."