The building superintendent was inclined to argue, but Bob cut him short. “This is no time for words,” he said. “Do as you’re told or I’ll file a charge against you for interfering with the work of a federal officer.” Actually Bob didn’t know whether he had that power or not, but the words sounded well and the threat did what was intended—the superintendent changed his tone and agreed to halt the burning of any more wastepaper or refuse. Bob turned back from the telephone and Jacobs looked at him with a brighter face. “I don’t know what’s going to happen to me,” he said, “but I feel better for having told you.” “I’ll help you all I can,” promised Bob heartily, turning to call for Lieutenant Gibbons. The intelligence officer opened the door almost instantly and Condon Adams and Tully Ross crowded in close behind him. “Well, can you solve the mystery for us now?” asked Adams, his voice heavy with sarcasm. “I think so,” replied Bob. “Let’s have it, then.” “Hardly. Solve it in your own way. Remember that I’m working with my uncle on this case. You have the invaluable help of Tully.” “That’s enough of smart cracks like that,” replied Adams, his face flushing a little. “I want to know what Jacobs said.” “I’m making my report direct to Mr. Edgar. You’ll have to get it from him.” With that Bob left the room and went directly to the office of the federal chief, Lieutenant Gibbons trailing at his heels. Waldo Edgar listened intently while Bob recounted what Jacobs had told him. “I rather sensed what his story would be,” mused the chief investigator. “Don’t you believe it?” asked Bob. “Yes, every word of it. Just another case of an older and bullying brother taking advantage of a weaker one. It looks like Jacobs has supplied us with the key information we have been groping for. Good work, Bob.” “I’m afraid I don’t deserve any congratulations. Adams turned up Jacobs as a suspect.” “True enough, but Jacobs would never have talked for Adams or any of the rest of us. The important thing is that he did talk to you. Now what are you planning?” Bob told of the letter from Maryland and of his orders to the building superintendent. “The postmark on that letter should give us a clue to where the gang took my uncle,” he said. “There isn’t much chance of finding it, but it’s worth the time and effort.” Waldo Edgar’s eyes brightened. “You’re going to do, my boy. It’s things like that that count. You never can tell when even the tiniest slip of paper is going to give you the key to the case you’re working on.” The chief agent turned to Lieutenant Gibbons. “You’re staying on the case with Bob?” he asked. “I’m going to try and keep up with him,” smiled the intelligence officer. “Splendid. Then we’ll expect your uncle and the missing radio paper within the next twenty-four hours, Bob.” Chapter XXVIII WASTE PAPER ★