The Tom Corbett Space Cadet Megapack. Carey Rockwell

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 my line of work. All I know is that, without a doubt, the black cloud is nothing more than dirt. Plain ordinary dirt! And it comes from the area in and around Venusport. As a matter of fact, certain particles I analyzed lead me to believe it came from the exposition site!”

      Hawks looked at Newton dumbfounded. “By the craters of Luna, man, we’re a 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 he suddenly smiled and turned to Claude. “As soon as that exhaust is cleared, blast off for Venusport, Lieutenant. I’m going to find out who dirtied up the sky!”

      * * * *

      Two hours later, when Captain Strong returned to his hotel in Venusport with 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. Tom quickly related their suspicions of Wallace and Simms.

      “And we’ve watched them every night, sir,” Tom concluded. “I don’t know what it is, but something certainly is going on in that shack they use for an office.”

      “Yes, sir,” agreed Astro, “and no one is going to fool me about a rocket ship. I know when they blast off loaded and return light.”

      Strong turned to Hawks who said quietly, “Wallace and Simms are the only ones in this whole area that blast off regularly without a customs search.”

      “You mean,” stammered Strong, “Wallace and Simms are dumping”—he could hardly say the word—“dirt in space?”

      “They have a ship. The cadets say the ship blasts off loaded and returns light. 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 some rocket-blasting good answers!”