Free The Great Airport Mystery by Franklin W. Dixon

Tyson’s story, the Hardys drove the man back to the camera shop to pick up his car. He said little more to shed any new light on the mystery and was obviously relieved when the boys drove off.
    When they reached home, Frank and Joe discussed the information they had gathered that day. “I’m convinced,” said Frank, “that Lieber and this Williams are mixed up in the Stanwide case.”
    â€œSo far, nearly all our suspects are company employees,” Joe commented. “How does this fellow Williams figure in?”
    â€œIt’s possible that he’s part of the racket, but working from the outside,” Frank suggested.
    The boys recalled Jerry Madden’s remark about Lieber’s being Peterson’s pal. They wondered if this meant that the chief pilot himself was involved in the thefts.
    â€œAnd it doesn’t surprise me that Art Rodax fits into the picture,” said Joe. “I knew he had a secret reason for not wanting us around the plant.”
    At that moment the telephone rang. The caller was Randy Watson. The pilot said that he had managed to rent an aircraft suitable for a long-distance flight from an operator at Lockwood Airport. This field was about two hundred miles from Bayport.
    â€œI’ve already been there and flown the plane back,” he said. “She checks out fine. We’ll be ready to roll any time in the morning.”
    â€œGood,” Frank answered. “Joe and I will be at the airport early. We can’t risk missing Peterson and Lieber’s departure.”
    At dinner the boys packed some light luggage. Mrs. Hardy and Aunt Gertrude tried to hide their anxiety when they heard the coming flight was to trail Peterson and Lieber, but an expression of concern crossed Mrs. Hardy’s face.
    â€œDon’t take any unnecessary chances,” she begged. “And keep in constant touch with us.”
    Frank and Joe promised to do this. They assured the women that the trip was only routine, and that they would be away not more than two or three days.
    â€œTwo or three days!” Aunt Gertrude exclaimed. “If you catch those thieves the first day, why can’t you come home? That’s where you belong, anyway!”
    The boys grinned and Joe said, “Why, Aunty, the longer the chase the more fun.”
    â€œFun nothing!” she stormed. “A lot of danger—unnecessary danger for a couple of growing boys!” Miss Hardy’s tirade ended only because she was called to the telephone.
    Mr. Hardy, on the other hand, made no objection to the trip. “Best of luck, boys,” he said.
    The following morning the boys started for the airport as soon as dawn broke. When they arrived, the Hardys spotted a sleek, highly polished twin-engine turbo-prop plane parked on the Ace Air Service ramp.
    â€œThat must be the plane Randy rented!” Joe exclaimed, pointing. “My, what a beauty! Wish I could fly her!”
    Frank grinned in anticipation. “It sure looks as if we won’t have any trouble keeping up with Peterson in that!”
    The boys put down their bags and approached the plane for a closer look. Just then Randy Watson came running out of the operations building.
    â€œHey, fellows!” he shouted excitedly. “Come here, quick!”
    The young detectives ran to meet him.
    â€œWhat is it?” Frank called. “Something wrong?”
    â€œI just tried to phone you at home,” Randy answered, “but you had already left. It’s about the Stanwide cargo plane!”
    â€œWhat happened?” Joe asked.
    â€œPeterson and Lieber left hours ago!” Randy said, trying to catch his breath. “They took off late last night!”

CHAPTER XII
    The Cave Clue
    THE Hardy boys wasted no time. Moments later, they were dashing up the circular stairs to the Bayport control tower.
    â€œIs Lou Diamond here?” Frank asked as they burst into the room.
    â€œNo,” answered a