"As soon as he gets here, I'll touch it off," the bearded man said. "Everything set, de Jong?" "Everything ready, Dr. Gomes," one of his assistants assured him. The door at the rear of the control-cabin opened, and Juan Murillo, the seismologist, entered, followed by an assistant. Murillo was a big man, copper-skinned, barrel-chested; he looked like a third-or fourth-generation Martian, of Andes Indian ancestry. He came forward and stood behind Gomes' chair, looking down at the instruments. His assistant stopped at the door. This assistant was not human. He was a biped, vaguely humanoid, but he had four arms and a face like a lizard's, and, except for some equipment on a belt, he was entirely naked. He spoke rapidly to Murillo, in a squeaking jabber. Murillo turned. "Yes, if you wish, Gorkrink," he said, in the English-Spanish-Afrikaans-Portuguese mixture that was Sixth Century, A.E., Lingua Terra. Then he turned back to Gomes as the Ulleran sat down in a chair by the door. "Well, she's all yours, Lourenço, shoot the works." Gomes stabbed the radio-detonator button in front of him. A voice came out of the PA-speaker overhead: "In sixty seconds, the bombs will be detonated ... thirty seconds ... fifteen seconds ... ten seconds ... five seconds, four seconds, three seconds, two seconds, one second...." Out on the rolling skyline, fifty miles away, a lancelike ray of blue-white light shot up into the gathering dusk--a clump of five rays, really, from five deep shafts in an irregular pentagon half a mile across, blended into one by the distance. An instant later, there was a blinding flash, like sheet-lightning, and a huge ball of varicolored fire belched upward, leaving a series of smoke-rings to float more slowly after it. That fireball flattened, then spread to form the mushroom-head of a column of incandescent gas that mounted to overtake it, engorging the smoke-rings as it rose, twisting, writhing, changing shape, turning to dark smoke in one moment and belching flame and crackling with lightning the next. The armor-tender began to pitch and roll; it was all the engineer and one of the assistants could do, together, to keep it level. "In about half an hour," the large young man told the girl, "the real fireworks should be starting. What's coming up now is just small debris from the nuclear blast. When the shockwaves get down far enough to crack things open, the gas'll come up, and then steam and ash, and then the magma. This one ought to be twice as good as the one we shot three months ago; it ought to be every bit as good as Krakatoa, on Terra, in 59 Pre-Atomic." "Well, even this much was worth staying over for," the girl said, watching the screen.