Rawson sprang as the big rock let go. It, too, crashed deafeningly upon the floor and rolled sluggishly downward beside the high hummock of glass that the first rock had become. They bulked hugely in the passage. They were eight or ten feet high, reaching across from one wall to the other.
Above them was still a space of four feet; Rawson estimated it carefully while he looked at the ceiling above. Then he shook off Smithy's hand that was dragging at him and returned to the attack; for now, above the top of the barricade he had built, white ribbons of vapor were streaming. He had to shout to his utmost to make Smith hear above the shrill shriek of the blast.
"Steam!" he screamed into Smithy's ear. "Live steam! We could never make it—before we got to the top we'd be cooked to a pulp. I've got to block it, got to seal it off." A whole section of the ceiling tore loose as he spoke, and the wind raised its voice like the scream of a wounded animal—or the cry of an overwhelmed and stricken people—as it tore through the space that remained.
t whipped the molten drops as they fell and made of them a deadly rain. Rawson, staring through the clouds of hot steam that now wrapped him about, called to Smithy to take Loah to safety, and kept the flame where it should be—until at length the last aperture was closed, the last gap in the wall filled in. And even after that Rawson kept the flame still playing above that wall till he had melted rock and more rock that flowed down to make the barrier a single heavy, solid mass.
Steam was coming now from the narrow cleft where the green light had flashed out to bar their way. But that was simple, and he sealed the gap shut with his flame.
He was gasping. The radiant heat from that molten mass had been torture that his naked body could never have borne but for the desperate necessity that drove him.
Smithy and Loah were again beside him. "Now," he choked, "we can go, but if there are any cross passages I'll have to block them too."
"There aren't," said Smithy, and added: "I thought you were crazy. You've saved us all, Dean; we never could have made it to the top. That steam was getting hot—hot as if it had come right out of hell."