An autistic teen newly on the run, Piper misses her getaway bus to aid a sea dragon, and gets tangled with Irish gods from myth on a flying pirate ship. MacLir, guardian of the seas, doesn't spend time with mortals anymore, but he's fascinated by Piper, a girl trying to find her courage and a new home. When teens start going missing near the faerie mounds, MacLir and Piper decide to join the search. In the process, they find something they didn't know they needed-each other.