mulations of plunder, give up all their fliers and armament,
and above all, the import of metals was forbidden them. For,
strangely enough, none of the metallic elements was to be found on
Ganymede. All their weapons, all their ships, were forged of metals
from the other planets.

It was now five years since Ganymede had been admitted once again to
the Planetary League, after suitable declarations of repentance. But
the prohibitions still held. And Grant placed small faith in the
sincerity of the repentance.

The Chief was speaking.

"We've called you in--Miro and I," he said, in his usual swift,
staccato manner, "because we've agreed that you are the best man in
the Service to handle the mission we have in mind."

Grant said nothing.

"It's a particularly dangerous affair," the Chief continued. "Five
great space-fliers, traveling along regular traffic routes, have all
vanished within the space of a month--passengers, crews and all. Not a
trace of them can be found."

"No radio reports, sir?"

"That's the most curious part of the whole business. Everyone of the
fliers was equipped with apparatus that could have raised the entire
solar system with a call for help, and yet not the tiniest whisper was
heard."

* * * * *

The Chief got up and paced the floor agitatedly. It was plain that
this business was worrying him. Miro continued to sit calmly,
seemingly indifferent. "It's uncanny, I tell you. Gone as though empty
space had swallowed them up."

"You've applied routine methods, of course," Grant ventured.

"Of course," the Chief waved it aside impatiently. "But we can't
discover a thing. Battle fliers have patrolled the area without
success. The last ship was literally snatched away right under the
nose of a convoy. One minute it was in radio communication, and the
next--whiff--it was gone."

"Where is this area you mention?" Already Pemberton's razor-edged
brain was at work on the problem.

"Within a radius of five million miles from Jupiter. We've naturally
considered placing an embargo upon that territory, but that would mean
cutting off all of the satellites from the rest of the system."

Miro stirred. His smooth slurred voice rolled out.

"And my planet would suffer, my friend. Alas, it has already suffered
too much." He evoked a sigh from somewhere in the depths of his barrel
chest, and tried to cast up his small red eyes.

Grant suffered too, a faint disgust. Da