The Melted Coins by Franklin W. Dixon

they do.”
    Frank took a plunge by asking bluntly, “Do you folks know an Elmont Chidsee?”
    There was not a moment’s hesitation. “Yes. Of course. He’s visiting upstairs right now. I understand he’ll stay overnight.”
    Joe rolled his eyes and said to Frank, “Oh, boyl That spells trouble!”
    â€œDid you say trouble?” Mrs. Rideau asked.
    â€œYes. We’re sorry you had this trouble,” Joe said quickly. “But if the police know all about it, I feel that you’re safe enough, at least from outside prowlers.”
    Mrs. Rideau excused herself and went to the kitchen to turn off the stove. The doctor, meanwhile, shuffled downstairs to put his coins away.
    Frank and Joe had an opportunity to talk things over. “The Rideaus are very naive not to suspect their tenants,” Frank remarked.
    â€œWe’ll just have to protect them,” Joe decided.
    The boys laid out a plan, and when Mrs. Rideau returned, Frank said that they would like to sleep in the Rideaus’ basement that night.
    â€œThat would be fine,” she said. “In fact, there’s a cot in the old dental office already. We can put another one there.”
    â€œBut,” Joe added, “first we’ll go into the barn as if we were planning to spend the night there. Then the prowlers will be thrown off.”
    â€œRight,” Frank went on. “And if they should happen to break into the house, Joe and I will grab them!”
    Mrs. Rideau chuckled and said, “My, you are brave boys. But our dogs would grab the ruffians before you had a chance!”
    While supper was being prepared, the Hardys joined the doctor in the basement. He showed them the coin vault and took them to his old dental office, where they would sleep.
    â€œI never sold any of my equipment,” he stated proudly, and pointed to the chair, the tools, and his drill. “That’s an air drill. Fine instrument. I always bought the best.”
    The Hardys returned to the dining room, where Mrs. Rideau served a succulent beef stew along with a generous green salad. All the while Frank and Joe listened for sounds from upstairs. If Chidsee was there with the professors, he was keeping mighty quiet.
    When darkness came, Frank and Joe took flashlights and their bags and went to the barn. They talked for half an hour, watching the upstairs windows of the Rideau house. Several times figures moved back and forth, but they were too indistinct to be recognized.
    Finally Frank said, “Okay, Joe. Ready to go to the dentist?”
    â€œPlease, not the air drill!” Joe protested.
    They crept through the darkness, opened the back door quietly, and descended into the basement.
    â€œI don’t think anyone saw us,” Frank said as they stretched out on the cots.
    The boys decided to spell each other with guard duty during the night. Frank slept first while Joe watched. At the end of two hours the younger boy roused his brother.
    â€œYour turn,” he said. “I didn’t hear a sound.”
    Some time past midnight, Frank was startled by a faint rattling noise, then he heard footsteps coming slowly down the basement stairs. He alerted Joe and gave the high sign for quiet.
    Both rose quickly and stood on either side of the door. They could hear the knob being turned.
    They held their breath and tensed to spring. The door opened. Frank flicked on the light.
    There stood Dr. Rideau!
    â€œAll right boys, it’s only me,” he whispered hoarsely. “You can turn the light off.”
    â€œWhat are you doing here?” Joe asked, irritated by the needless fright.
    â€œI just wanted to see if you fellows were all right.”
    â€œBut what about that rattling sound we heard?”
    â€œHm!” The doctor thought for a moment, then put his hands in his bathrobe pocket and jiggled some coins. “I guess this is what caused it.”
    â€œI suppose it is,” Frank said,