The story takes place on lovely Chincoteague Island, Virginia. The characters from "The Hidden Key", Megan, Kendall, and Jack, are back again. But they aren't alone in their adventures. They are joined by Jack's best friend, Brian, a self-appointed pirate expert, along with Chincoteague native, Ashley, and a young deaf girl, Maddie. The children are busy planning treasure hunts and making up a secret code based on the fingerspelling alphabet. They see a pirate treasure coin exhibit and in searching for their own treasure, track real pirates across the island.