"Say-y-y," broke in the detective. "Who the devil are you, and what do you mean by breaking into my examination and stopping it?" Carnes tossed a leather wallet on the table. "There are my credentials," he said in his quiet voice. "I am chief of one section of the United States Secret Service as you will see, and this is Mr. Berger, my assistant. We were in the bank, engaged on a counterfeiting case, when the robbery took place. We have had a good deal of experience along these lines and we are merely anxious to aid you." Sturtevant examined Carnes' credentials carefully and returned them. "This is a Chicago robbery," he said, "and we have had a little experience in robberies and in apprehending robbers ourselves. I think that we can get along without your help." "You have had more experience with robberies than with apprehending robbers if the papers tell the truth," said Dr. Bird with a chuckle. * * * * * The detective's face flushed. "That will be enough from you, Mr. Sherlock Holmes," he said. "If you open your mouth again, I'll arrest you as a material witness and as a possible accomplice." "That sounds like Chicago methods," said Carnes quietly. "Now listen to me, Captain. My assistant and I are merely trying to assist you in this case. If you don't desire our assistance we'll proceed along our own lines without interfering, but in the meantime remember that this is a National Bank, and that our questions will be answered. The United States is higher than even the Chicago police force, and I am here under orders to investigate a counterfeiting case. If I desire, I can seal the doors of this bank and allow no one in or out until I have the evidence I desire. Do you understand?" Sturtevant sprang to his feet with an oath, but the sight of the gold badge which Carnes displayed stopped him. "Oh well," he said ungraciously. "I suppose that no harm will come of letting Winston answer your fool questions, but I'll warn you that I'll report to Washington that you are interfering with the course of justice and using your authority to aid the getaway of a criminal." "That is your privilege," replied Carnes quietly. "Mr. Winston, will you answer Mr. Berger's question?" "Why, I asked him because he was right close to the money and I thought that he might have reached through the wicket and picked it up. Then, too--" He hesitated for a moment and Dr. Bird smiled encouragingly. "What else?" he asked. "Why, I can't exactly tell. It just seemed to me that I had heard the rustle that bills make when they are pulled across a counter. When I saw them gone, I thought that he might have taken them. Then when I turned toward him, I seemed to hear the rustle of bills behind me, although I knew that I was alone in the cage. When I looked back the money was gone." "Did you see or hear anything like a shadow or a person moving?"