Jonathan, Brooke and Ty are at the beach with seaman and his grandson. They find a skeleton. It's quite obvious the person was killed by boomerang that struck the head which was embedded in it. And the person was holding a scrimshaw. They notice something carved into it which is quite obviously a map. So they try to find out who the victim is and who the killer is. In the meantime, the seaman is keeping something from them.