In this new adventure Leo San Juan, Don Andres, Teodora and the Alebrije go to Guanajuato Ciy in Mexico to stop the mummies, whom inexplicably have awaken, and rescue their friend Xochitl. With the help of Luis and a new friend they meet Leo discovers the terrible secret of Rosseau, the richest man in town while the rest of the gang realizes that everything has been a setup.