Penny shook her head. "The door has a special catch so I know it couldn't have opened by itself. Susan, I believe someone has sneaked into the garage since we left it!" Susan's eyes dilated with fear. Involuntarily, she took a step backwards, turning toward the kitchen door. Penny caught her by the hand. "Don't tell Mrs. Gallup or she'll go into hysterics. Let's find out if there really is anyone in the garage before we call the police." At first Susan hung back, but when she found that Penny was determined to investigate the garage alone, she reluctantly followed her chum down the path. Cautiously, they peeped into the garage. It appeared to be deserted. "I'll get Dad's flashlight from the sedan pocket," Penny whispered. She tiptoed across the cement floor. Groping about inside the car she found the light, but before she could turn it on she was startled to hear a slight sound overhead. Penny's heart began to beat a trifle faster. She was almost certain that someone was hiding in the little room above the garage. In former years it had been occupied by a chauffeur whom Mr. Nichols employed, but now that the detective drove his own car it was used only for the storage of a few old boxes and trunks. "Don't you dare go up there!" Susan whispered tensely, sensing the thought in her chum's mind. "It isn't safe." "It's safe enough if you stand guard here at the door," Penny insisted. "If anything goes wrong scream for Mrs. Gallup." Before Susan could stop her she tiptoed across the cement floor and quietly crept up the stairway leading to the storage room. Reaching the top step Penny paused to listen. She could hear no unusual sound, yet a certain intuition warned her that someone was in the room. Systematically, she flashed the beam of her light over the walls. Nothing appeared amiss. "My imagination is running riot tonight," she thought in disgust. "There's no one here." She started toward the stairway, but paused, unable to rid herself of the conviction that all was not as it should be. Then her light chanced to focus for an instant upon an old trunk in one corner of the room. Beside it in a crumpled heap lay an old rug. From her father Penny had learned to be an unusually keen observer. She was positive that upon her last visit to the storeroom, the carpet had covered the trunk, protecting it from dust. Summoning her courage, she cautiously approached the trunk. She paused to listen again. Distinctly, she could hear the sound of soft breathing. Suddenly she flung back the lid. A man cowered inside. "Don't make a move," Penny warned coolly, blinding him with the light. Protected as she was by the darkness, he could not know that she had no weapon. "Don't shoot!" he pleaded, stepping from the trunk with hands held above his head. It was then that Penny observed that her prisoner was a mere boy. He did not appear to be more than a year or two older than herself.