It's the summer of 1977, and you're supposed to be having the time of your life vacationing with your high school friends before you all go your separate ways for college. Then the storm hits, capsizing your yacht and stranding you on a wild, uncharted island that isn't on any map, with a handful of mismatched teens and no way home.

As you weld your fractured group into a found family—building shelter, surviving a paradise that's as dangerous as it is beautiful, and falling for at least one of your four magnetic companions—the island begins to reveal impossible wonders. Flying seahorses. Lights that bend time. A wedding frozen mid-celebration for fifty years. And a chaperone whose obsession with the island's secrets may be the most dangerous thing of all.