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.

The approach of the Yaqui was like a slow dark shadow of gloom. If it seemed so to the stricken Gale what must it have been to Rojas? He appeared to sink against the wall. The Yaqui stole closer and closer. He was the savage now, and for him the moment must have been glorified. Gale saw him gaze up at the great circling walls of the crater, then down into the depths. Perhaps the red haze hanging above him, or the purple haze below, or the deep caverns in the lava, held for Yaqui spirits of the desert, his gods to whom he called. Perhaps he invoked shadows of his loved ones and his race, calling them in this moment of vengeance.

Gale heard--or imagined he heard--that wild, strange Yaqui cry.