Bull's-eye -- Knight in the woods -- Hidden passage -- Gauntlet is thrown -- Pay the piper -- Vanished! -- Which way to china? -- Hack, you're it -- Ring of fire -- Fly-by-knight -- Phantom archer -- Cracking the code -- Marble shaft -- Unexpected ally -- Gallant knights.

Frank and Joe accompany a college champ preparing for a national championship in the sport of orienteering, but accidents begin to happen and they must find out who is trying to stop him from competing. Frank and Joe are thrilled to be taking part in the grand opening celebration of a new maze in Cape Breton, Nova Scotia. By solving puzzles-their specialty-they could win a valuable prize! But once they arrive, the teens soon have a new puzzle to solve: The owner and designer of the maze, Chezleigh Alan Horton, suddenly disappears. As the boys make their way through a labyrinth of suspects, they face a new twist. Can Frank and Joe unravel a decade-old riddle to save the renowned mazemaster?