n with an exit
indicated. Get some one to go with you; find the place and wait for me
there. I can find the secret entrance from the Graveyard from this
negative--and I'm going through it."

Balcom, in the passageway between the Graveyard of Genius and the
Automaton's den, was livid with fury. He realized that his picture had
been taken, surmised that the secret passage would be found and that
some assault on the den would be attempted. But he had had no time to
locate the camera, which Locke had hidden well, nor had he dared to
search longer for it when he heard Locke bounding down the stairs from
the library.

Accordingly, he had retreated and hastened back through the passageway
into the Automaton's den.

"Quick!" he shouted to the horde of emissaries in the place. "Bring
dynamite, electric wires, and a rack-bar. They think they have us
trapped. But if they try to follow me here, I tell you it will mean
certain death to them."

The emissaires hastened to obey him. They brought the explosive and the
means to detonate it, and carried the stuff into the passageway, where
they made the connections. An emissary stepped forward and volunteered
to use the rack-bar when the time came, but Balcom waved him away.

"No," he growled. "No one can take my revenge from me. I'll do the
killing."

The emissaries fell back and went into the den.

Balcom was making some final adjustments when the great rock separating
the passageway from the Graveyard of Genius swung slowly on its balanced
hinges.

Startled from his work, even though he had expected the thing, Balcom
looked up, and in the passageway caught a glimpse of the dim outline of
his arch-enemy, Locke.

Balcom had been right. Locke had found the clue to the secret entrance
to the tunnel.

He worked feverishly to complete the final connection, but almost before
he finished Locke charged and the battle was on.

Up and down the passageway they fought. Although Locke was the younger
man, yet in Balcom he found a giant of strength.

It was a fight between these two alone, for no emissary, no Automaton,
now entered that passage of death.

Neither uttered a sound. Neither had a weapon. It was the primitive
struggle of man to man for life.

But now Locke's youth and clean living began to tell in his favor and he
sensed that his adversary was weakening. He redoubled his efforts.

After a particularly vicious blow from Locke, Balcom threw up his hands
and toppled ove