peered through
the window into the living room, where an oil lamp, turned low, dimly
lighted the interior, which he saw was unoccupied. Going to the door
he pushed it open and entered the apartment. All was still within. He
listened intently for some slight sound which might lead him to the
victim he sought, or warn him from the apartment of the girl or that of
von Horn--his business was with Professor Maxon. He did not wish to
disturb the others whom he believed to be sleeping somewhere within the
structure--a low, rambling bungalow of eight rooms.

Cautiously he approached one of the four doors which opened from the
living room. Gently he turned the knob and pushed the door ajar. The
interior of the apartment beyond was in inky darkness, but Number
Thirteen's greatest fear was that he might have stumbled upon the
sleeping room of Virginia Maxon, and that if she were to discover him
there, not only would she be frightened, but her cries would alarm the
other inmates of the dwelling.

The thought of the horror that his presence would arouse within her,
the knowledge that she would look upon him as a terrifying monstrosity,
added new fuel to the fires of hate that raged in his bosom against the
man who had created him. With clenched fists, and tight set jaws the
great, soulless giant moved across the dark chamber with the stealthy
noiselessness of a tiger. Feeling before him with hands and feet he
made the circuit of the room before he reached the bed.

Scarce breathing he leaned over and groped across the covers with his
fingers in search of his prey--the bed was empty. With the discovery
came a sudden nervous reaction that sent him into a cold sweat.
Weakly, he seated himself upon the edge of the bed. Had his fingers
found the throat of Professor Maxon beneath the coverlet they would
never have released their hold until life had forever left the body of
the scientist, but now that the highest tide of the young man's hatred
had come and gone he found himself for the first time assailed by
doubts.

Suddenly he recalled the fact that the man whose life he sought was the
father of the beautiful creature he adored. Perhaps she loved him and
would be unhappy were he taken away from her. Number Thirteen did not
know, of course, but the idea obtruded itself, and had sufficient
weight to cause him to remain seated upon the edge of the bed
meditating upon the act he contemplated. He had by no means given up
the