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 over backward—in the direction of the rack-bar itself.