In medieval Spain, a witch named Mamba was tortured and skinned alive as punishment for her crimes. Her skin and organs were then used to make a cursed board game named after her. The player who wins the game is granted a wish; however, the player who loses the game is killed in a fashion predicted by the game.
In the present day, Jason acquires the board game from a disabled shop owner named Malek. After rain forces his friend Tomas's beachhouse party to end, another partygoer, Erica suggests that the remaining friends — including Tomas, Lisa, Elena, Miguel, and Pablo — play the game.
Pablo is eliminated and takes Tomas's car to get a beer. He falls off a cliff and a group of crabs attacks him, gouging out his eyes and killing him. Miguel, Lisa, Elena, and Tomas also lose the game, before Gary Piquer arrives and informs the group of Pablo's death, cutting the game short.
The group attends Pablo's funeral, where Erica realizes that his death mirrors the game's prediction. Tomas, Lisa, and Miguel travel to Miguel's family's empty wood-cutting factory to have a photo shoot. Lisa begins to feel unwell and leaves with Tomas. Alone, Miguel falls into a group of snakes that kill him.
Jason and Erica start a romance. While they are in Jason's car, they witness ghostly versions of Pablo and Miguel, before learning about Miguel's death. They meet Tomas, Lisa, and Elena and explain they suspect that the friends are dying because of the game. Lisa becomes sicker; the following morning, she has aged into an old woman and is rushed to the hospital.
Jason, Erica, and Elena tell Detective Izar their theory about the game. Lisa soon dies, prompting Jason, Erica, and Tomas to seek answers from Malek. They find Malek at his home, but he is no longer disabled; he explains that he won the game and wished to be cured of his disability. Meanwhile, Elena is traveling home when she is involved in a car accident and burns to death. Jason, Erica, and Tomas go to Jason's house, where they find Detective Izar looking for the game. Jason and Erica escape with it, but Tomas is caught by the detective. When he attempts to escape, Izar shoots him dead.
At Tomas's beachfront house, Jason and Erica decide to play the game in the hope that they can win and wish for it to be a week in the past so their friends will be alive again. Erica is eliminated and learns that her death will involve the sea; Jason wins and will get his wish as long as he passes the game on to another person. Erica realizes that she must die for Jason to get his wish, so she enters the sea. Jason rushes out to save her, but Detective Izar shows up and leaves with the game. Erica emerges from the sea now possessed by Mamba, who grants Jason his wish that they never played the game. However, Jason and his friends end up trapped in an endless time loop as a result of his wish, forced to relive the week again and again.
