“You ought to know,” grinned Frank. “You’ve been here often enough. But it’s rather a queer coincidence that we should be sent to guard it.” They entered the cellar where the bulk of the goods was stored. “So this is the famous ‘cellar’ that the old man was always muttering about,” remarked Frank, as he looked curiously about him. “The identical place,” replied Tom. It was a long and wide cellar with many bales and barrels stored in it. The only light was from a lantern which had been lighted by the squad they had just relieved, and which hung from a beam at one end, leaving most of the place in darkness. CHAPTER XXV FOILING THE GERMAN PLOT “This cellar’s a nice place to tell ghost stories in,” remarked Bart. “It would make a fellow creepy to be in here all by his lonesome.” “I thought I heard a noise down in that end of the cellar,” said Tom. “You’re dreaming,” said Billy. “Come out of your trance.” But just then there was another noise that all of them heard. It sounded like a scratching noise, or as though someone were inserting a key in a lock. “Quick!” whispered Frank. “Hold your guns ready and get down behind these bales.” Like a flash they obeyed and waited with bated breath for what should come next. The scratching continued. Then slowly a door swung open at the far end of the cellar and a figure advanced carrying a candle. He walked with faltering steps, and as he drew nearer they could see that it was Mrs. Edsall’s father. He paused at a part of the wall that was in shadow and seemed to be searching for something. Then with a sigh of satisfaction he found it. He pressed a spring and a concealed door opened, revealing a small aperture. The old man reached in his hand and brought out a roll of papers. He glanced over them for a moment in the light of the candle. Then he swung the door shut and turned to go. But just then there was a startling interruption. From behind a barrel in whose shadow he had been hiding, a man leaped out, and throwing himself on the old man grasped the papers and tore them from him. The attack was stunning in its suddenness, but the man had scarcely straightened up before the Army Boys had swarmed out of their concealment and seized the intruder. He put up a sharp fight, but in the grasp of those sinewy arms he was helpless. In a moment they had overpowered him. The old man stood by, shaking as though with a palsy. “Now,” said Frank sharply to the intruder, “what does this mean? Tom, bring that lantern here and let’s have a look at this man.” Tom did so, and as the light fell on the man’s face he uttered an exclamation of surprise that was echoed by Frank and Billy. “Why,” said Frank, “it’s the man we saw in Luxemburg!” “I don’t know where you saw me and I don’t care,” answered the stranger angrily. “I only warn you that you’ll get in trouble if you interfere with me in the discharge of my duty. I’m a member of the United States Secret Service.”