the wall in the last few days. These creatures
literally haunt the jungles around here now--I think they've been
drawn here from all over the asteroid."

Ricky looked wonderingly at Gloria and the others who were entering
the hut. "Lance, who are all these people? Are they prisoners of Dark
too?"

"Yes, we're prisoners," Hugh Murdock told him bitterly, with a savage
glance at Kenniston. "We're prisoners because your brother sacrificed
us all to get back here and save _your_ neck."

"Lance, you didn't do that?" Ricky exclaimed in distress.

"I had to, Ricky," Kenniston protested. "It meant your life if I
didn't."

"Of course," Murdock agreed ironically. "What importance are we,
compared to saving your young brother's life?"

Kenniston spoke slowly, to Murdock and Gloria and the others. "It
wasn't merely Ricky's life at stake that made me sacrifice you all. It
was more than that. I tried to tell you before, but you wouldn't
listen."

* * * * *

Kenniston went across the hut and brought back the square black
medicine-case of his young physician-brother. He opened it, and out of
the vials and instruments inside he took a square bottle of milky
fluid.

"This is what I sacrificed everything to save," Kenniston said simply.

They all stared. "What is it?" Gloria asked, puzzled.

"It's Ricky's discovery," Kenniston said. "It's a preventative and
cure for gravitation-paralysis."

Captain Walls, himself an old-time space-man, was first of the group
to appreciate the significance of the statement. The captain gasped.

"A preventative for gravitation-paralysis? Kenniston, are you _sure_?"

Kenniston nodded gravely. "Yes. Ricky had been working on the problem
a long time, back in the Institute of Planetary Medicine. He thought
he'd found a way to prevent gravitation-paralysis, the most awful
scourge of all the outer System, the thing that's doomed so many
space-men. But his formula required rare elements found only in the
outer planets.

"Ricky and I," he continued, "went out there and secured those elements.
He made up this formula, and tried it on a gravitation-paralysis case--a
space-man who's lain paralyzed for years. The formula was designed to
strengthen the human nervous system against the shock of varying
gravitations, to re-establish an already damaged nerve-web. And it
worked."

Kenniston's voice was husky as he concluded. "It worked, and that
living log became a man aga