Her thoughtful gaze followed his figure until it disappeared around the far corner of the hall.

A few hours afterward, the six-man crew of the Cetus X-500 was in the Space Command planetarium receiving final briefing from General Forester. The spacious dark room gleamed with thousands of lights, each one of them accurately depicting a prominent star in the heavens. General Forester pointed to a pulsing hazy spot against the starlight.

“This is the R-cloud,” he said. “It’s really invisible, of course, but it’s made visible in here to show you its location. Its apparent direction is a few degrees south of the bright star Procyon in the constellation Canis Minor, almost on the plane of the ecliptic. Some of our scientists believe the cloud was an eruption from Procyon about fifteen years ago. Starting eleven light years away and traveling nearly at the speed of light, it’s just getting here.”

“Am I right, sir,” Lieutenant Swenson said, “in assuming that there will be a colossal explosion when our bombs contact it?”

“Undoubtedly,” the general assured him. “For that reason you will release the guided missiles when you reach the edge of the solar system. Unless the cloud changes course, which we have no reason to believe that it will do, the point of contact will be ten billion miles distant from the sun. Our scientists believe that is a safe enough distance from us. The flash will probably be of novalike proportions.”

The general turned over to Rob and Lieutenant Swenson, the navigator, stacks of charts and tables that had been prepared showing the exact location of their ship and the cloud every minute of the way. It was a project requiring infinitely careful calculation, and Rob marveled at the mathematical ingenuity that had gone into the prodigious task. A miniature of the much larger electrometer which had first detected the menacing cloud had been installed in the rocket fighter so that Rob could continually keep it in his electronic sights, so to speak, at all times.

“You will blast off at 1835, seventeen minutes from now,” the general concluded, “and cross planetary orbits under full atomic thrust to Titan. You will land at our base there, have a final mechanical check, and load your bombs. General Carmichael, the chief there, will advise you of any conditions that might have changed since you left here. After that you will blast off to your rendezvous with the R-cloud. Any questions?”

There were none. Like himself, Rob noted that his companions seemed to be rather numbed by the enormity of their task. It seemed almost ridiculous that six persons could be expected to accomplish the incredible job plotted for them.


“My sister said she talked to you,” Clay Gerard said to Rob when the Cetus X-500 had blasted off and her crew had unbuckled from acceleration couches.