Follow along as the Hardy brothers Joe and Frank go on mysterious adventures and crack open clues! Perfect mysteries to read for children and teens! This set includes the following 6 books: #7 The Secret of the Cave #8 The Mystery of Cabin Island #9 The Great Airport Mystery, #10 What Happened At Midnight #11 While the Clock Ticked #12 Footprints Under the Window Franklin W. Dixon is a pen name used by a variety of authors writing for the classic series, The Hardy Boys. The first and most well-known “Franklin W. Dixon” was Leslie McFarlane, a Canadian author who contributed 19 of the first 25 books in the series. Other writers who have adopted the pseudonym include Christopher Lampton, John Button, Amy McFarlane, and Harriet Stratemeyer Adams. #7: Triggered by the disappearance of a brilliant young professor, this mystery takes the Hardy boys first to Kenworthy College, where they find a puzzling message on an examination paper. But then, a new clue is unearthed that sends the young detectives to the Honeycomb Caves. After many dangerous encounters, Frank and Joe discover a powerful searchlight in one of the craggy caverns along the seacoast. #8: In The Mystery of Cabin Island, the eighth book in the incredibly popular, long-running series, Frank and Joe Hardy encounter several dangerous setbacks as they search for Johnny Jefferson and some antique stolen medals. A special treat for Hardy Boys fans and any reader who's new to the series! #9: Valuable electronic parts containing platinum are being stolen from shipments made by Stanwide Mining Equipment’s cargo planes, and Frank and Joe are called upon to assist their world-renowned detective father solve the baffling case. While posing as Stanwide employees, the boys look into the truth behind the chief pilot’s death at sea.