Ryan and Kendra have come to Maple Harbour on the BC coast to spend their summer holidays with their aunt and uncle. They're expecting a leisurely holiday swimming and playing on the beach with their cousins Claire and Nathan. Claire, however, has other ideas - exploring islands in her sailboat and searching for sunken treasure. But what's hidden on mysterious Whalebone Island? Have the four of them come across a secret that others don't want discovered? Children...