The room he sought was on the second floor, and the Lizard had mounted the steps from the basement to the first floor when he was brought to a sudden stop by a noise from the floor above him.  The Lizard listened intently.  No, he could not be mistaken.  Too often had he heard a similar sound.

Some one was tiptoeing across the floor above.  The Lizard was in the hallway close beside the stairs when he realized the footsteps were coming toward the stairway, and a moment later that they were cautiously descending.  The Lizard flattened himself against the wall, and if he breathed his lungs gave forth no sound.

If one may interpret footsteps—­and the Lizard, from the fund of a great experience, felt that he could—­those descending the stairway from above him might have been described as nervous and repressed; for at least they gave the Lizard the impression of one who desired to flee in haste and yet dared not do so, for fear of attracting attention by the increased noise that greater speed might entail.

At least the Lizard knew that those were the footsteps of no watchman, but whether it be guardian of the law or fellow criminal the Lizard had no wish to be discovered.  He wondered what had gone wrong with Murray’s plans, and, suddenly imbued with the natural suspicion of the criminal, it occurred to him that the whole thing might be a frame-up to get him; and yet why Murray should wish to get him he could not imagine.  He ran over in his mind a list all those who might feel enmity toward him, but among them all the Lizard could cast upon none who might have sufficient against him to warrant such an elaborate scheme of revenge.

The footsteps passed him and continued on toward the foot of the stairs where was the main entrance which opened upon the street.  At the door the footsteps halted, and as the Lizard’s eyes bored through the darkness in the direction of the other prowler the latter struck a match upon the panel of the door and lighted a cigarette, revealing his features momentarily but distinctly to the watcher in the shadow of the stairway.  Then he opened the door and passed out into the night.

The Lizard, listening intently for a few moments to assure himself that there was no one else above, and that the man who had just departed was not returning, at last continued his way to the foot of the stairs, which he ascended to the second floor.  Passing through the outer office, he paused a moment before the door to Compton’s private office, and then silently turning the knob he gently pushed the door open and stepped into the room.

Beyond the threshold he halted and pressed the button of his flash-lamp.  For just an instant its faint rays illumined the interior of the room, and then darkness blotted out the scene.  But whatever it was that the little flash-lamp had revealed was evidently in the nature of a surprise, and perhaps something of a shock, to the Lizard, for he drew back with a muttered oath, backed quietly out of the room, closed the door after him, and, moving much more swiftly than he had entered, retraced his steps to the fifth window on the alley, and was gone from the scene with whatever job he had contemplated unexecuted.