Mary Beth, a museum tour guide, takes a group of school detention students on a secret museum tour, telling them, with wooden figures, the story of a Mexican town called San Angel from the Book of Life, holding every story in the world.
On the Day of the Dead, La Muerte, ruler of the Land of the Remembered, and Xibalba, ruler of the Land of the Forgotten, see Manolo Sánchez and Joaquín Mondragon competing for the love of María Posada. They strike a wager: if María marries Manolo, Xibalba will no longer interfere in mortal affairs, but if she marries Joaquín, La Muerte and Xibalba will swap realms. However, Xibalba cheats by giving Joaquín his Medal of Everlasting Life, which grants the wearer invincibility.