In agony now, both mental and physical, cold and sick and weak, Gale gripped his rifle and aimed at the struggling forms on the ledge. He pulled the trigger. The bullet struck up a cloud of red dust close to the struggling couple. Again Gale fired, hoping to hit Rojas, praying to kill Mercedes. The bullet struck high. A third--fourth--fifth time the Remington spoke--in vain! The rifle fell from Gale's racked hands.

How horribly plain that fiend's intention! Gale tried to close his eyes, but could not. He prayed wildly for a sudden blindness --to faint as Thorne had fainted. But he was transfixed to the spot with eyes that pierced the red light.

Mercedes was growing weaker, seemed about to collapse.

"Oh, Jim Lash, are you dead?" cried Gale. "Oh, Laddy!...Oh, Yaqui!

Suddenly a dark form literally fell down the wall behind the ledge where Rojas fought the girl. It sank in a heap, then bounded erect.

"Yaqui!" screamed Gale, and he waved his bleeding hands till the blood bespattered his face. Then he choked. Utterance became impossible.

The Indian bent over Rojas and flung him against the wall. Mercedes, sinking back, lay still. When Rojas got up the Indian stood between him and escape from the ledge. Rojas backed the other way along the narrowing shelf of lava. His manner was abject, stupefied. Slowly he stepped backward.

It was then that Gale caught the white gleam of a knife in Yaqui's hand. Rojas turned and ran. He rounded a corner of wall where the footing was precarious. Yaqui followed slowly. His figure was dark and menacing. But he was not in a hurry. When he passed off the ledge Rojas was edging farther and farther along the wall. He was clinging now to the lava, creeping inch by inch. Perhaps he had thought to work around the buttress or climb over it. Evidently he went as far as possible, and there he clung, an unscalable wall above, the abyss beneath.