Mallory said respectfully, "Yes, sir. All figures have been checked and double checked. We're point oh-oh-one on course. Forced speed, point thirty-nine above normal." "Checked and double checked," said Captain Algase, "is good enough most of the time. But this trip is special. And vitally important. Forty thousand innocent lives depend on our reaching Io damn soon! Remember that, Mallory. All of you remember that." The stern lines of his face eased a trifle. "It's been a hard shuttle, I know. A brutal, punishing trip. And we've all been under a terrific strain. But our difficulties are nothing compared to those of the garrison and the honest colonists of New Fresno. They're looking to us for aid, and we're bringing them aid. "That is, someone aboard this ship is. I honestly don't know who that person is. No one knows except the man himself, the commander of the SSP Intelligence Department on Earth, and maybe someone at New Fresno. But he _is_ on board, either an officer, sailor or passenger, and he _is_ carrying to Io the plans for the new ray weapon recently perfected by the SSP Ordnance Bureau. "Those plans will enable our New Fresno garrison to subdue this mysterious uprising on Io. That's why the _Libra_ is traveling at forced speed. That's why we must redouble every normal precaution to insure our reaching the Io colony. That's why, too, we must keep our eyes open; watch even each other. What's the matter with you, Norton?" * * * * * Norton had started suddenly. Now he muttered, red-faced, "Sorry, sir. Sudden light in the visiplate. It looked like a meteoride." "There's nothing there now," said the skipper. But Chandler repeated, "Watch each other, Captain? I don't get it. We're all pledged and trusted members of the Solar Space Patrol, aren't we? We all live by the SSP motto. I don't see--" He fingered his breast insignia, that tiny, golden rocket emblazoned with the words, _Order out of Chaos_. "I don't see why we should--" "Because," explained the skipper grimly, "wherever there's an uprising there are converts to the new cause, traitors to the old. Where there are plans, there are spies to steal them. That's not a warning from H.Q.; that's plain, old-fashioned horse-sense. I fought through the Rollie Rebellion, you know. After the Grantland massacre I discovered that one of my own messmates was in the pay of the Mercurians. "I won't say for sure that there is a spy aboard the _Libra_. But if there is, we must give him no opportunity to learn anything. Weary or not, we must remain on the alert at all times. But I needn't say any more. Finished, Mallory?" "Yes, sir. Log in order, sir." "Very good. You may retire. Chandler, you seem to be fagged." Bud said, "One more yawn and I'll be a zombie."