But not entirely helpless. Colonel Culver had been right: their rifles outranged the flame-throwers. And Rawson, looking past that first burst of rifle fire, saw the one flame that had reached them whip upward as its owner fell. Others of the Reds came crowding in after, and the jets of their weapons made little areas of light as they crashed to the floor. Then Colonel Culver took charge of the retreat. Ahead of them and behind them was impenetrable darkness; only the nearby walls were illumined by the torch that Loah had been forced to turn on. And out of that darkness at any moment might come devastating flames. Culver detailed two men as a rear guard and two others to run ahead a few paces in advance. At intervals of a minute or two their rifles would crack, and the echoes would be pierced by the whining scream of ricochets, as their bullets glanced from the walls. "We may not need them up ahead," Culver shouted to Rawson. "I don't understand it. The place seems deserted--there were plenty of them here before!" "They've got something else to think of," Rawson shouted in reply. "I killed Phee-e-al--he was their leader. But they're after us now. They'll be running through other passages, cutting in ahead of us." The tunnel turned and bent upward. For a full half mile they ran straight in a stiff climb. Between gasping breaths Colonel Culver shouted hoarsely: "Won't it ever turn? If they bring up their damned heat-ray machines they'll get us on a straightaway like this!" Then Smithy's voice outshouted his with a note of hope: "We're almost there; I remember this place. There's where we mounted the searchlight. They've ripped everything out. Up ahead, one turn to the right, then a quarter mile, then a turn toward the crater. That runs straight for a mile, but there's a field gun at the bottom of the volcano. We'll be safe when we're on that last stretch." * * * * * Ahead of them the rifles of the two who ran in advance crashed out in a fury of fire as a green glow appeared. But this time the flame did not die; and Rawson, staring with hot, wide-opened eyes, saw that the ribbon of green swept transversely across the tunnel. He could hardly stand when he came to a stop. Beside him Loah was swaying with weariness. The walls echoed only the hoarse, panting breath of the men. Then they crept slowly forward, where the passage went steadily up. Loah's light was out; she had slipped the cap on the torch at the first sight of that green.