His teeth were gritted.

With the sudden loss of mass, the ship lurched. Bert had to struggle for a moment to adjust the angle of its flaming stern-jets, and bring it back on course. In another few seconds he cut the stern-jets out entirely, and opened the fore-nozzles wide to check excess speed, and reestablish the Prometheus in a stable orbit around Titan. One that could last forever without additional thrust.

"Well, the Big Pill is on its way—for better or worse," Alice remarked. "Half of our job is done."

But time had to pass before that metal colossus could drive itself and fall the thousand miles to the bleak, dried-out hills below. And the space ship hurtled on, to leave the point of coming impact far beyond the horizon. This, the Kraskows knew, was fortunate for them. The solid bulk of Titan would be the shield between them and holocaust. No human eyes could have looked directly on such a holocaust, at a range of a mere thousand miles, and not be burned from their sockets.

Bert and Alice noticed that the Space Patrol craft were no longer pursuing them. Alice switched on the radio again but only jangled sounds came through.

"Now for the last half of our job, Allie," Bert said. "First we attach shoulder-pack jets to our spacesuits."

This was accomplished a few seconds before the stupendous flash of the Big Pill's explosion blazed beyond the horizon. The dark curve of Titan's bulk was limned against thin white fire that streamed outward toward the stars like comet's hair. The spectacle looked like a much-enlarged color-photo of a segment of a solar eclipse. The glare on the other side of Titan was so intense and far-reaching that the night-portions of huge Saturn and his other satellites, and the shadowed part of the fabulous, treasure-filled Rings, all hundreds of thousands of miles away, registered an easily perceptible flicker. But in airless space, of course, no sound was transmitted.

Alice's face went pale. Bert did not stop doing what must be done—adjusting the timing system in the black case beside his pilot seat, and looking with a final, intense glance along the cable which led back through the hull of the ship to a silvery, pipelike thing around which the thousands of tons of sinister black ingots were stacked. It was the primer-cap of another kind of subatomic fury.

About the white fire beyond the horizon, hardly dimming at all after its first dazzling flash, neither Alice nor Bert said anything. Maybe their awe and concern were too great. But already long fingers of incandescent gases were jetting and flowing over the hilltops, as if to catch up with the speeding ship.

Bert Kraskow knew pretty well what was going on where the Big Pill had struck the crust of Titan. First, there had been that stupendous blast. Then, inconceivable blue-white incandescence, like the heart of a star, began gnawing more gradually into the walls of the gigantic crater that had been formed. A chain-reacting process was now spreading through the silicates and other components of Titan's crust. It was a blunt and terrible inferno.

But to the scientist's view, chemical compounds were being broken apart; atoms were being shattered, and recast in new forms, as floods of neutrons, and other basic particles raced like bullets through their structure. On a small scale, here was something that was like the birth of the universe.

Bert found his voice at last. "The ship is firm in its orbit around Titan, Allie. The primer is set for thirty minutes from now. And we're approaching position above camp again. So here's where we bail out."

The Kraskow's closed their helmet face-windows and jumped from the airlock together. Flame-propelled by their shoulder-pack jets, they darted downward toward the sad, rolling hills that curved away under the weak light of the distance-shrunken sun. It was hard to believe that eons ago, before most of Titan's air and water had leaked away into space, those hills had been green with life.

Even with an ugly, red-lit vapor pouring and spreading over the arc of Titan's edge, they thought of such things.

heir helmet radiophones were full of static from intense electromagnetic disturbances, so that it was hard to converse.

But presently Alice shouted: "Bert! It's funny that we don't see the ship from camp anywhere in space. They must have gotten our warning to blast off with everybody. Radio reception was clear as a bell, then!... Wait! Somebody's trying to call us now...."

Bert strained his ears to penetrate the scratchy noises thrown up by the atomic holocaust that he had set off, and hear the words spoken blurredly by a familiar voice:

"... Bert ... Alice.... This is Lawler.... Rockets of ship won't function.... So ... can't leave ... camp.... Two Space Patrol boats cleared Titan with some ... women.... Too small ... few passengers.... Most ... stranded here.... Bert—what?... I think ... Lauren...."

The rest of the words were drowned in a cataract of static.

Bert gulped. His mouth tasted suddenly sour with near-panic. "Lauren," he grated, his voice like a file. "Again. It would be a long chance that the ship broke down just by coincidence. He doctored those rockets and probably got clear in his own spaceboat. Leave it to him to make the use of the Big Pill look like disaster. And it can be that, now, with people left in the danger zone, losing their heads, acting foolishly."

Bert felt much more than just bitter, furious chagrin. His fellow colonists might lose their lives. He was responsible. He had launched a gigantic experiment recklessly.

"All we can do is get back to camp as fast as possible," Alice shouted above the static. "Come on, Bert! Bear down on the jets!"

So they hurtled at even greater speed toward the surface of Titan below. Meanwhile, faintly luminous vapors continued to pour over the hills from the direction of the terrible glow that fringed the horizon. Minutes before they reached the ground, hot, dusty murk thickened around them. It blew against them like a devil's wind.

They began to use their jets to brake speed. The camp was all but lost to view in the thickening haze. They landed heavily a mile outside it and went rolling for a few yards after the impact. Dazed, they staggered up.

For a while their impressions were blurred, as if they struggled through some murky, cobwebby nightmare. Once more on Titan, silent as death for unthinkable ages, there were howling wind-sounds that found their way to Alice and Bert dimly through their oxygen helmets. Often the hot blast bowled them over, but they arose and kept on toward camp.

Bert took a Geiger counter, pencil-size from his chest-pouch. In it, flashes of light replaced the ancient clicking. It flickered madly. This meant that outside their shielding spacesuits was radioactive death. The gases of the wind that howled around them, had been in part released from chemical compounds, but more had been transmuted from other elements of the rock and dust in the crust of Titan, in that atomic vortex where the Big Pill had struck. Those gases were so new that they were tainted with the fires of their birth—saturated with radioactivity.

"It's nothing that we didn't expect, Allie," Bert grated into his helmet-phone, as if to reassure himself as well as his wife. "We knew beforehand."

His arm was around Alice, supporting her unsteady steps. Through blowing clouds of dust and gas that had surpassed hurricane force, they reached camp. Through the murk they saw that the wind had flattened and scorched every airdome. But there was no one in sight.

"The people must be inside the ship!" Alice shouted. "Even if it can't fly, it can protect them! There it is, undamaged!..."

"Yeah," Bert agreed, but he knew that her cheerfulness was a little like grabbing at a straw.

Then Alice had another