A thrilling descent into Aztec mythology awaits! Twelve-year-old twins Carol and Johnny Garza's lives are forever changed when their mother mysteriously disappears. Shipped off to relatives in Mexico, they discover a shocking family secret: their mother is a nagual, a shapeshifter, and they've inherited her powers.

To rescue their mother, Carol and Johnny must journey into the Aztec underworld, Mictlan, facing dangerous creatures and powerful gods. Can they master their newfound abilities and overcome the trials that await them, or will they be trapped in the land of the dead forever?

Perfect for middle grade readers who love action-packed fantasy with a rich cultural twist. Winner of the American Library Association's 2016 Pura Belpré Author Honor.