about eight o'clock. Then at nine I made my rounds to see if everything was all right. I have to look for signs of fires or burglars or anything wrong, you know."
"How many offices were lighted up?"
"Smythe's and Moffett's and Mr. Middlebury's; that's all I remember, sir."
"Where were you when this boy called you?"
"On the stairs, going up to the sixth floor."
"This is the only elevator running at night?"
"Yes, sir. I'm supposed to keep run of this boy and see that he stays till midnight."
At this moment two officers appeared at the entrance. Astro turned to McGraw. "Tell them to keep hidden outside," he said, "and nab any one leaving the building. Now we'll go up and see what has happened."
As the five entered the car, Astro, whose look had fallen on the rubber matting on the floor, moved over nearer the elevator boy, and, pushing him a little aside, picked up a slip of paper on which he had been standing. It proved to be blank; but the Seer, after scrutinizing it, put it away in his pocketbook. The boy slammed the door and the car started up the shaft. Astro touched the boy's arm.
"Stop at the ninth floor!" he commanded.
The elevator boy looked up in surprise; but pulled the lever and threw open the hall door.
"You wait here," said Astro to Thompson and the lad. "Come on, McGraw. We'll see Moffett first."
They walked down the hall and around a corner till they came to a lighted door. Astro, without knocking, threw the door wide open. It was a small room, and at a roll-top desk a man jumped up quickly in conster-
