CHAPTER 4
Tom glanced at the astral chronometer over the control board of the_Polaris_ and sighed with relief. It was nine P.M. He turned to theintercom.
"Attention, please! Attention, please! The exhibit is now closing forthe night. All visitors will kindly leave the ship immediately." Herepeated the announcement again and turned to smile at the lastlingering youngster ogling him before being yanked toward an exit by atired and impatient mother.
The hatch to the radar bridge opened and Roger climbed down the ladderto flop wearily in the pilot's seat in front of the control panel.
"If one more scatterbrained female asks me how the astrogation prismworks," groaned the blond cadet, "I'll give it to her and let her figureit out for herself!"
Astro joined them long enough to announce that he had made sandwichesand brewed hot chocolate. Tom and Roger followed him back to the galley.
Sipping the hot liquid, the three cadets looked at each other withoutspeaking, each understanding what the other had been through. EvenAstro, who normally would rather talk about his atomic engine than eat,confessed he was tired of explaining the functions of the reaction fuelforce feed and the main valve of the cooling pumps.
"The worst of it is," sighed Astro, "they all pick on the same valve.What's so fascinating about one valve?"
Tom's job on the control deck was less tiring, since his was more of acommand post, which demanded decisions, as conditions arose, rather thana fixed routine that could be explained. But even so, to be asked overand over what the astral chronometer was, how he could read time onEarth, Mars, Venus, Titan, Ganymede, and all the satellites at the sametime was wearing on the toughest of young spirits.
Eager to forget the grueling day of questions and answers, the cadetsturned their thoughts to the mysterious midnight activity that had beentaking place around the spaceship concession during the last ten days.
"I just can't figure out what those guys are up to," said Roger, blowingon his hot chocolate. "We've watched those guys for over a week now andno one has even come near them with anything that could be smuggled."
"Could be a small package," suggested Astro, his mouth full of hamsandwich. "Somebody could take a ride and slip it to them."
"Hardly," said Tom. "Remember, that ship blasts off like she's loaded tothe nose with cargo. And then she comes back like a feather. You cantell by the sound of her jets. So it wouldn't be anything small enoughfor someone to carry."
"Yeah, I guess you're right," agreed Astro.
"Well," said Tom finally, "I'm stumped. I think the only thing left todo is to decide if it's anything important enough to tell Captain Strongabout. Working on the _Polaris_ twelve hours a day and staying up allnight to watch those two jokers has me all in."
Roger and Astro looked at each other and then silently nodded theiragreement.
"O.K.," said Tom, "we'll go to the skipper's hotel in Venusport and tellhim the whole thing. Let's see what he makes of it."
* * * * *
At that moment Captain Strong was in the office of ExpositionCommissioner Mike Hawks trying to make sense out of a series of reportsthat had landed on the commissioner's desk. Hawks watched him carefullyas he studied the papers.
"You say this is the ninth report you've received since the fair opened,Mike?" asked Strong finally.
Hawks nodded. He hadn't known whether to laugh off or seriously considerthe nine space skippers' reports that the sky over the exposition sitewas dirty.
"Yes, Steve," he said. "That one came from the skipper of an expressfreighter. He blasted off this morning and ran through this so-calleddirt. He thought it was just a freak of nature but reported it to be onthe safe side."
"I don't suppose he took a sample of the stuff?"
"No. But I'm taking care of that," replied Hawks. "There's a rocketscout standing by right now. Want to come along?"
"Let me finish these reports first."
"Sure thing."
As Strong carefully checked each report, Commissioner Hawks rose andbegan to stride restlessly back and forth across the spacious office. Hestopped in front of the window and stared out over the expositiongrounds, watching the thousands of holiday visitors streaming in and outof the buildings, all unaware of the strange mystery in the sky abovethem. Hawks' attention was drawn to the giant solar beacon, a huge lightthat flashed straight out into space, changing color every second andsending out the message: "Quis separabit homo"--Who shall separatemankind?
This beacon that at the beginning of the exposition had reached into theblack void of space like a clean bright ray was now cloudy andmurky--the result of the puzzling "dirty sky."
"All right, Mike," Strong announced suddenly. "Let's go."
"Get anything more out of those reports?" asked Hawks, turning back tohis desk.
"No," replied the Solar Guard officer. "They all tell the same story.Right after blast-off, the ships ran into a dirty sky."
"Sounds kind of crazy, doesn't it?"
"Crazy enough to check."
Hawks pressed a button on the desk intercom.
"Yes, sir?" replied a metallic voice.
"Have the rocket scout ready for flight in five minutes," Hawks ordered.He snapped off the intercom without waiting for a reply and turned toStrong. "Let's go, Steve."
The two veteran spacemen left the office without further comment androde down in the vacuum elevator to the highway level. Soon they werespeeding out to the spaceport in Hawks' special jet car.
At the blast-pitted field they were met by a young Solar Guard officerand an elderly man carrying a leather case, who were introduced asLieutenant Claude and Professor Newton.
While Claude prepared the rocket scout for blast-off, Strong, Hawks, andNewton discussed the possibility of lava dust having risen to greatheights from another side of the planet.
"While I'm reasonably sure," stated Newton, "that no volcano has eruptedrecently here on Venus, I can't be sure until I've examined samples ofthis so-called dirt."
"I'll have Lieutenant Claude contact the University of Venus," saidHawks. "Their seismographs would pick up surface activity."
Claude stuck his head out of the hatch and reported the ship ready forblast-off. Strong followed the professor and Hawks aboard and strappedhimself into an acceleration chair. In a moment they were blastingthrough the misty atmosphere of Venus into the depths of space.
Fifteen minutes later, Hawks and Strong were standing on the hull of theship in space suits, watching the professor take a sample of a dirtyblack cloud, so thick it was impossible to see more than three feet.Strong called to the professor through the spacephone.
"What do you make of it, sir?" he asked.
"I wouldn't want to give you a positive opinion without chemical tests,"answered the professor, his voice echoing in Strong's fish-bowl helmet."But I believe it's one of three things. One, the remains of a largeasteroid that has broken up. Two, volcanic ash, either from Venus orfrom Jupiter. But if it came from Jupiter, I don't see how it could havedrifted this far without being detected on radar."
Now, holding a flask full of the black cloud, the professor started backto the air lock.
"You said three possibilities, professor," said Strong.
"The third," replied the professor, "could be--"
The professor was interrupted by Lieutenant Claude calling over theintercom.
"Just received a report from the University of Venus, sir!" said theyoung officer. "There's been no volcanic activity on Venus in the lastten years serious enough to create such a cloud."
Strong waited for the professor's reaction, but the elderly man wasalready entering the air lock. Before Strong and Hawks could catch up tohim, the air-lock hatch slammed closed.
"Hey," exclaimed Strong, "what does he think he's doing?"
"Don't worry about it, Steve," replied Hawks. "He probably forgot wewere out here with him, he's so concerned about this dirt. We'll justhave to wait until he's out of the air l
ock."
The Solar Guard officer nodded, then looked around him at the thickblack cloud that enveloped the ship. "Well," he said, "one of theprofessor's theories has been knocked out."
"Yes," replied Hawks. "Which means this stuff is either the remains of alarge asteroid or--"
"The third possibility," finished Strong, "which the professor neverexplained."
Suddenly the air-lock hatch opened again and the two spacemen steppedinside. Closing the hatch behind them, they waited until the pressurewas built up again to equal that of the ship, and then they removedtheir helmets and space suits.
_The hatch opened again and the two spacemen entered theair lock_]
Leaving the air lock and walking down the companionway, Hawks suddenlycaught Strong by the arm.
"Have you considered the possibility of this cloud being radioactive,Steve?" he asked.
Strong nodded slowly. "That's all I've been thinking about since I firstheard about it, Mike. I think I'd better report this to CommanderWalters at Space Academy."
"Wait, Steve," said Hawks. "If you do that, Walters might close theexposition. Wait until you get a definite opinion from ProfessorNewton."
Strong considered a moment. "I guess a few more minutes won't make a lotof difference," he said finally. He realized how important theexposition was to his old friend. But at the same time, he knew whatwould happen if a radioactive cloud suddenly settled on the city ofVenusport without warning. "Come on. Let's see what the professor has tosay about this stuff."
They found the professor on the control deck bending over a microscope,studying samples taken from the flask. He peered intently into theeyepiece, wrote something on a pad, and then began searching through thepages of a reference book on chemicals of the solar system.
Lieutenant Claude stepped up to Hawks and saluted sharply. "Power deckreports they've got a clogged line, sir. It's in the gas exhaust."
Strong and Hawks looked at each other, and then Hawks turned to theyoung officer. "Send a couple of men outside to clear it."
"Aye, aye, sir," said Claude, and then hesitated. "Shall the men wearlead suits against possible radioactivity, sir?"
Before Hawks could answer, Newton turned to face the three men. Theprofessor was smiling. "No need to take that precaution, Lieutenant. Inever did tell you my third opinion, did I, Captain Strong?"
"Why, no, you didn't, sir," said Strong.
The professor held up a sheet of paper. "Here's your answer. Nothing butplain old Venusport topsoil. Pure dirt!"
"What?" exclaimed Hawks hastily, reaching for the paper.
"Well, blast me for a Martian mouse," muttered Strong under his breath."But how?"
Newton held up his hand. "Don't ask me how it got here. That isn't myline of work. All I know is that, without a doubt, the black cloud isnothing more than dirt. Plain ordinary dirt! And it comes from the areain and around Venusport. As a matter of fact, certain particles Ianalyzed lead me to believe it came from the exposition site!"
Hawks looked at Newton dumbfounded. "By the craters of Luna, man, we'rea thousand miles over the exposition!"
The professor was stubborn. "I can't tell you how it got here,Commissioner Hawks. But I do know it's Venusian dirt. And that's final!"
Hawks stared at the elderly man for a second, still bewildered. Then hesuddenly smiled and turned to Claude. "As soon as that exhaust iscleared, blast off for Venusport, Lieutenant. I'm going to find out whodirtied up the sky!"
* * * * *
Two hours later, when Captain Strong returned to his hotel in Venusportwith Mike Hawks, he was surprised to see the three cadets of the_Polaris_ crew slumped, sleepy-eyed, on a couch in the lobby.
"What are you doing here, boys?" he asked.
The three cadets came to attention and were wide awake immediately. Tomquickly related their suspicions of Wallace and Simms.
"And we've watched them every night, sir," Tom concluded. "I don't knowwhat it is, but something certainly is going on in that shack they usefor an office."
"Yes, sir," agreed Astro, "and no one is going to fool me about a rocketship. I know when they blast off loaded and return light."
Strong turned to Hawks who said quietly, "Wallace and Simms are the onlyones in this whole area that blast off regularly without a customssearch."
"You mean," stammered Strong, "Wallace and Simms are dumping"--he couldhardly say the word--"_dirt_ in space?"
"They have a ship. The cadets say the ship blasts off loaded and returnslight. And we've got the sky full of dirt. Venusian dirt!"
"But why?"
"I suggest we go out to the exposition grounds right now and ask them!"said Hawks coldly. "And believe me, they'd better have somerocket-blasting good answers!"