The rich Le Domas household hosts a generations-long custom of enjoying a recreation on the marriage evening of recent additions to the household. In a flashback a few years in the past, younger Alex Le Domas and his brother Daniel witness the killing of a person named Charles, who has simply married their aunt Helene.
Thirty years later, Alex – who has been estranged from his household for years – marries a younger lady named Grace on the Le Domas property. At midnight, after becoming a member of a household initiation, Grace participates in a session the place she is required to attract a card from a mysterious wood field and play the sport written on the cardboard with the Le Domas household.
Collaborating within the custom with Grace are Alex, Daniel, their father Tony, their mom Becky, Daniel’s spouse Charity, Alex’s drug-addicted sister Emilie, Emilie’s husband Fitch Bradley, and Helene, who’s Tony’s older sister. Tony explains that his great-grandfather Victor Le Domas made a take care of a person named Mr. Le Bail the place Le Bail would assist create the Le Domas fortune if the Le Domas household established the aforementioned custom.
Grace attracts from the field a card that reads “conceal and search.” Believing the sport to be innocent, Grace leaves to cover within the property whereas the Le Domas household, excluding Alex, arm themselves with vintage weapons to search out Grace.
Alex manages to search out Grace earlier than his household, and the pair witness Emilie by chance kill one of many property’s maids. Alex informs Grace that conceal and search is the one possibility that may very well be drawn from the field that may immediate the Le Domas household to attempt to kill Grace. The Le Domas household believes that in the event that they fail to kill Grace earlier than daybreak, they’ll all die as agreed by Victor Le Domas and Mr. Le Bail – implied to be both Devil or a demon – a long time earlier. Towards his household’s needs, Alex guarantees to Grace that he’ll assist her escape the property having not informed her in regards to the ritual for worry that she would depart him. Alex then heads to the home’s safety room after instructing Grace to go to the exit on the kitchen.
Whereas in search of the exit, Grace encounters a second maid, who’s inadvertently killed, and Daniel who, like Alex, hates the character of his household thus permitting Grace to run. Alex deactivates the property’s safety cameras and unlocks the doorways of the home. Nevertheless, he’s found by his household who seize him for his betrayal. Grace manages to flee the home after eluding the household’s butler Stevens.
A 3rd maid is by chance killed by Emilie. Stevens informs the household that Grace has left the home however guarantees to seize her. Grace manages to go away the property grounds after being shot within the hand by Emilie’s son Georgie, and being lower within the again going by way of a fence. Stevens chases after Grace in a automobile however she manages to quickly incapacitate him after he will get out to restrain her.
Making an attempt to drive off with the automobile, Grace contacts the car help firm, however the automobile was reported stolen and so they disable it remotely, permitting Stevens to tranquilize and seize Grace. Whereas Stevens drives her again to the property, Grace causes him to crash the automobile, killing him. Nevertheless, Grace is found by Daniel who, understanding that Tony is secretly watching, knocks her out once more and recaptures her. The Le Domas household prepares to sacrifice Grace in a satanic ritual. After the household drink from a cup of wine as a part of the ritual, all of them start to vomit apart from Daniel who non-lethally poisoned the wine, coming to the idea that his household deserves to die.
In the meantime, Alex escapes his captivity. Daniel frees Grace and so they try to go away the home earlier than Daniel is shot and killed by Charity. After setting the home on hearth, Grace is pressured to struggle Becky and manages to beat her to loss of life with the field. Alex arrives and, considering that Grace killed each Becky and Daniel and understanding that she’s going to depart him ought to she survive, captures Grace for his household to sacrifice.
When the Le Domas household try to kill Grace as soon as extra, Grace manages to interrupt free and Helene reveals to the household that daybreak has damaged. Nothing appears to occur to the household, till Helene makes an attempt to interrupt the principles and kill Grace after daybreak has damaged. One after the other, every member of the Le Domas household, excluding Grace, explodes in a bloody mess. A determined Alex begs Grace for forgiveness; she replies that she needs a divorce and throws her wedding ceremony ring at him, simply earlier than he too explodes.
Whereas the home burns down, Grace briefly sees the spirit of Mr. Le Bail sitting in a chair, who seems to approve of her survival. As morning breaks, Grace sits on the property’s steps whereas it burns behind her and smokes a cigarette as first responders arrive. When one of many responders asks what occurred, Grace replies “In-laws.”