Eleven-year-old Caitlin Adams of Daphne, Alabama, and her grandfather look forward to adventures together on his visits. This time, she informs him of "a nagging sound to my hearing-superpower" and their need to hurry back to "Gator Alley," where first detected, to investigate. Their search leads to unimaginable experiences-phantom, bent on terminating her when closing in on its evil plan; alternate realms; and supernatural creatures. Caitlin gets unexpected protection from a mystical creature, but to overcome it, the phantom duplicates his magical feats. She seeks further aid from her cousin who also possesses superpowers. But will they be able to defeat the phantom-in the apparent last minutes of their and their grandfather's lives?