Kin

During a stay at a school camp, Héctor, Fausto and Emilia go into a cave in Palenque with the firm intention of scaring Joaquín, a classmate who is being bullied. Meanwhile, his classmates begin to receive messages from him and have terrifying apparitions that at first make them fear that it is revenge from beyond. In the end, they realize that they are clues to travel back in time to help Joaquín and the Mayan emperor boy.