Charlie has received a letter from the Land of the Dead--a dire warning from his grandmother concerning his (and the rest of La Liga's) impending demise. He doesn't have much to go on, but according to the letter, a mysterious incident in the past, known only as "The Five Donkeys," set in motion an unstoppable chain of events that will culminate in the total destruction of the Land of the Living.

Left with little alternative, Charlie, Violet, and Raúl enlist Esperanza's help to use forbidden calaca magic and travel back in time to the place where the trouble began: 1950s Cuba. But all they discover in the mountain rainforests of Havana is a trail of dark secrets. And the deeper they dig, the more questions they unearth, none of which help them decipher what La Mano Peluda is planning. But perhaps most alarming of all, the friends soon learn that they are not the only time travelers in town.

Pursued by an unspeakable evil, Charlie and Violet must race against time to untangle the past, present, and future before the world they love vanishes into history.