“You speak of _spies_. I heard references made to at least one this evening. Do you suspect any others?” asked the captain. “I know one other, sir. That one is the supervisor’s maid, Marie Debussy!” “Are you positive?” asked the general. “I am, sir. I have heard conversations between her and the doctor. I have seen her acting suspiciously and in conference with men that I was certain were enemy officers, and I have heard her holding telephone conversations that connected her with plots against our men.” “I wonder who she can be?” marveled the captain. “Who she is? She is Rosa von Blum, the famous German agent.” Both officers started, and stared at her in amazement. “I presume you also would like to know who this other spy, that you call Doctor Klein, is. He is Captain Carl Schuster of the German Secret Service, a man who, I have heard said, is perhaps the cleverest of the Imperial operators. You no doubt wonder how I have obtained this information. It was quite simple, not due to any unusual ability or cleverness on my part. I did not know definitely until last night, when he said upon opening the telephone conversation, ‘This is Carl! No, Carl Schuster--B One!’ I then knew. The revelation of Rosa von Blum’s identity occurred in a somewhat similar manner.” “This is most remarkable!” exclaimed Captain Boucher. “Remember what I told you, Boucher,” interjected the general. “I think you will agree with my expressed estimate of Mrs. Gray’s ability. I may say, Mrs. Gray,” he added, turning to the Overton girl, “that we have wondered about Doctor Klein, and that Miss Marshall has been working on his case, but without results beyond mere suspicion. Before the army reached the Rhine our operatives here reported their suspicions of him. That was the reason you were billeted in his house. I told Captain Boucher that if there was the slightest basis for our suspicions, you would discover that basis. We decided that nothing should be said to you of those suspicions. I wished to prove to the captain that my estimate of your ability was not influenced by the fact that you saved my life in the Argonne. We therefore gave you the opportunity to demonstrate, and you did.” “That was what I referred to when I told you you would be surprised when you had set yourself straight on the matter of the doctor,” spoke up Captain Boucher. “You doubted Miss Marshall too, and with very good reason. That shows what a clever worker she is. You and she will compare notes to-morrow. But this that you tell me about Schuster and von Blum is a blow between the eyes. I never even considered such a possibility. It should be some satisfaction to you to know that you have turned up two of the most dangerous agents in the enemy service. It surely is a source of satisfaction to us. I suppose we should have Mrs. Smythe dismissed to-morrow, General? Why not recommend that Mrs. Gray take charge as supervisor in her place?”