All Fun and Games

The story is set in Salem, Massachusetts, a city notorious for its witch hunts, and centers on the Fletcher siblings—Billie, Marcus, and Jo—growing up under their mother's care following their father's departure after sobriety. Their uncle Bob, who has been unemployed, lives with them, adding to the household's dynamics. Billie is socially active, while Marcus is a loner, and Jo sees himself as Marcus' only friend.

While cycling through the woods, Jo and Marcus hear voices and stumble upon a sinister cabin. Jo finds a knife and a diary inside, with Marcus suspecting the house belongs to a psychopath who manipulates their minds. They decide to leave, but Jo keeps the cursed knife, feeling an inexplicable connection to it.

Back home, Jo cleans the rusty knife, noticing the inscription 'I will play, I won't quit.' He begins to see visions of past violent incidents linked to the curse and unknowingly starts to be influenced by a demonic presence. Jo's behavior becomes increasingly erratic, sweating and obeying the demonic whispers.

Jo persuades Billie, her boyfriend Pete, her friend Sophie, Marcus, and Uncle Bob to play a game, but the demon's influence intensifies. Marcus is coerced into repeating the curse, which leads to demonic possession. Marcus's behavior turns violent, and he begins his killing spree.

Marcus, possessed by the demon, kills Uncle Bob during a game of Hangman and then heads to a party where he continues his rampage. He carves an 'X' on his forehead and terrorizes the guests, turning the party into a scene of chaos and bloodshed. Billie leaves the party shortly before Marcus arrives, sensing something is wrong.

The demon compels Marcus to play hide and seek, and he kills everyone at the party. Billie, Jo, and Sophie unite and decide to revisit the cabin to find answers. Meanwhile, Marcus, still possessed, becomes increasingly vicious as he seeks his family.

The diary reveals a tragic history of a woman accused of witchcraft who escaped with her son Daniel, seeking safety in the woods. The townspeople captured Daniel, carved an 'X' on his forehead, and murdered him in horrific ways—torching his body and slashing his throat. His spirit was cursed to seek vengeance through a vessel, which was used to torment others.

The mother, in her desperation, crafted a cursed knife from Daniel's bone and cast a spell to bind his spirit, causing Daniel to possess vessels and orchestrate gruesome games of torture and death, repeating endlessly until his spirit could be freed.

Billie, Jo, and Marcus confront Marcus's demonic possession, with Billie using a flashlight to weaken Marcus during a game of flashlight tag. Billie seizes the cursed knife and repeats the curse to stop Daniel from taking her over, fighting to free herself from his control. Jo volunteers to become the demon's vessel to save the others.

Jo stabs Daniel, who is in his demonic form, with the cursed knife, causing him to disintegrate into a black liquid. The curse is broken, and the evil spirit is vanquished. The surviving siblings witness the end of Daniel's torment and the curse's hold.

The morning after, Marcus turns himself into the police, overwhelmed by guilt and unable to explain the supernatural events. The trio manages to survive while protecting themselves from the cursed entity. The knife reappears mysteriously at the cabin, hinting the curse might not be entirely over.