“I only need to pass these guards and I can do it,” he said at last. “I know a secret entrance to the palace through the pinnacle of the highest tower. I fell upon it by chance one day as I was passing above the palace on patrol duty. In this work it is required that we investigate any unusual occurrence we may witness, and a face peering from the pinnacle of the high tower of the palace was, to me, most unusual. I therefore drew near and discovered that the possessor of the peering face was none other than Sab Than. He was slightly put out at being detected and commanded me to keep the matter to myself, explaining that the passage from the tower led directly to his apartments, and was known only to him. If I can reach the roof of the barracks and get my machine I can be in Sab Than’s quarters in five minutes; but how am I to escape from this building, guarded as you say it is?”

“How well are the machine sheds at the barracks guarded?” I asked.

“There is usually but one man on duty there at night upon the roof.”