Twelve-year-old Alexa Daley is spending another summer in Bridewell with her father. She looks forward to exploring the old lodge where she stays each year, with its cozy library and maze of passages and rooms. She's also eager to finally solve the mystery of what lies beyond the immense walls that were built to keep out an unnamed evil that lurks in the forests and The Dark Hills - an evil the townspeople are still afraid of.

As Alexa begins to unravel the truth about what lies outside the protective barrier she's lived behind all her life, she discovers a strange and ancient enchantment. Armed with an unexpected new power, Alexa exposes a danger that could destroy everything she holds dear - and change The Land of Elyon forever.