"Over three million miles--it can't be! Not the way it's pulling us now. Unless," he added thoughtfully, "it has a gravity grab equal to that of Jupiter at half the distance! Good Lord!" He tested instruments, gave experimental side thrusts with the Tuner, but they came back irresistably into the pull of the planet ahead. Hour after hour they came nearer. The planet resolved into a dark disc with a peculiar surrounding halo. "I don't like it," Janus reflected the thoughts of them all. "That light--where does it come from? Not the Sun! The Sun doesn't even touch Pluto!" "Maybe it has a Sun of its own," ventured Kaarj. "On the other side." "If it does, the sun moves right along with it in it's orbit!" "You can tell from here that the planet has no axial rotation," Brownell announced. He looked a little worried. "This gravity drag is getting worse. We're accelerating. Better get into your harness." He set the example, and the men followed. "I think I can control it with the Tuner in reverse, but it pays to be safe. You never can tell, out here; these are strange conditions." The planet was looming fast. The Professor's hand on the deceleration lever revealed the strain he was under. Below them now they glimpsed vast dark plains, and as they came nearer, huge stretches of forest. Mountains loomed. Far ahead was faint light, a few miles of "twilight strip" much as that on the planet Mercury. The Professor was heading for this strip but Mark didn't think they'd make it. They were losing altitude with sickening speed. Mark had a final vision of the little Professor tugging desperately on the deceleration lever, of huge greenish-gray plants coming up beneath them. Then a rending crash, a confusion of flying legs and arms. Just before Mark blanked out he knew their ship was still ploughing forward. III He came back to consciousness with a feeling of intolerable weight pressing him down. It was his own weight, he discovered as he tried lifting his head to look around. It was a terrific strain and he let his head fall back. None of the men were seriously injured. The bulging harness had saved them. They called out to each other, but couldn't move except to roll their heads from side to side. "Professor, did you say a gravity equal to that of Jupiter?" Dethman called out. "That, or more. And yet this planet has a diameter of scarcely a few hundred miles! Strange!" "Strange, he says," came from Driscoll. "What do we do now, just lay here for the rest of our lives?" "Let's see you do anything else," Kaarj said drolly. "Not me," Janus spoke. "You think I'll let this pee-wee world get me down? If I can only get to that Tuner control." "I'm afraid this is one kind of gravity it won't counteract," Brownell admitted ruefully. "This world must be condensed as tightly as a white dwarf star! A cubic inch of matter weighing hundreds of pounds!"