While staying at a secluded mansion, six young adults reveal their personal demons during an innocent game called Taboo. They reunite a year later, only to realize that one of them wants them dead for their moral transgressions.
When Christian Turner gathers together his fiancée Elizabeth and their friends Adam, Benjamin, Piper and Katie to celebrate their high-school graduation, they play the cheeky card game 'taboo' which anonymously confides their secret vices to paper. The following year Christian inherits the grand estate and invites them back for New Year's Eve. This time the games are far more serious, but go way weirder then anyone planned, with several unexpected twists.—KGF Vissers
Six friends, Christian, Elizabeth, Piper, Kate, Adam, and Benjamin, play a game which consists of "yes" and "no" questions that are to be answered anonymously. Once the cards are shuffled, the questions are read aloud and answered by another participant of the game. The questions are deeply personal, covering topics such as sex and incest. Some of the questions posed included "would you sleep with a relative?" and "would you have sex with a minor?"
A year later, the group all meet again at Christian's and Elizabeth's new mansion for a New Year's Eve dinner. The night goes well until the electricity powers out and a package arrives at the door containing six cards; written on them are the words, "prostitute, infidel, homosexual, rapist and hypocrite". These words are associated with the questions that were posed during the Taboo game that they played the previous year.
Horrified by the package, Elizabeth decides to get more wine to alleviate everyone's concerns. Adam, whose question was, "would you have sex with a minor", follows Elizabeth to the wine cellar and accuses her of arranging the delivery of the package. Elizabeth runs upstairs and tells her friends that she was attacked by Adam. When Christian and Elizabeth go back to the cellar, they find Adam with a knife to lodged in his stomach and the word "rapist" attached to the knife which was used to stab him
The couple joins the rest of the group downstairs. Piper, in her drunken state, brings up Christian's father's past affair with a prostitute. Once he impregnates her, he vanishes after his family discovers his infidelity. Piper then questions Benjamin's sexuality. He reveals that he is dating Kate to show his parents that he is not gay in order to keep his inheritance. Shortly after, as Elizabeth and Christian go to a room to speak privately, they discover Benjamin in their bathtub, killed via electrocution with the "homosexual" card beside the tub.
While Elizabeth begins to look for Christian, Kate approaches Elizabeth with a shotgun, accusing her and Christian of killing Adam and Benjamin. As Elizabeth runs downstairs to look for Christian, Elizabeth finds Piper murdered by means of a dog collar strangulation with the word "infidel" lying adjacent to her lifeless body. As Elizabeth continues to search for Christian, Kate confronts Elizabeth again, angered by the incessant accusation, Elizabeth attempts to shoot Kate, but much to her dismay, the gun was not loaded. Kate becomes infuriated so she decides to blindfold Elizabeth, and lead her to Christian's location using "hot" and "cold" signals. As Kate and Elizabeth reach upstairs, Christian shoots Kate in the head and the couple transport her body to the living room along with the other bodies.
Christian coerces Elizabeth to confess of setting up the game in order to expose the others' moral weaknesses and exploited their secrets as leverage for blackmail. Christian then reveals to Elizabeth that he is the killer and reasons that his motive was to protect Elizabeth because the group had become aware of her deception and they were going to take advantage of the dinner gathering to get revenge against Elizabeth. Shortly after his revelation, Christian discloses that the others have merely faked their deaths as a ruse to assure Elizabeth would confess to her deceit, astonished with these news, Elizabeth flees while Christian chases her. Meanwhile, Kate sets out to find Elizabeth's card from the game a year ago and discovers that Elizabeth divulged that she would have sex with a relative. Having no time to react, Kate is suddenly locked in the room.
Later, Christian finds Elizabeth, who tries to seduce him. She then reveals that she is Christian's sister from his father's affair; Christian accepts Elizabeth as his sister and devises a plan to kill everyone in the house to protect their newfound secret. He then proceeds to shoot Benjamin and Adam, bludgeon Piper with his shotgun, and stabs Kate with a pool cue. Once the murder spree is complete, Elizabeth demands Christian half of their father's fortune, and they negotiate the matter over dinner, only to find out that Christian has poisoned the wine. Elizabeth's final question of what will happen to Christian lingers unanswered as he too takes a glass of the poisoned wine to live up to his family's motto of "virtue, family, and justice."
