 What did Casey probably learn from this experience?
I never thought I'd mess around any of them, but things can sure happen. Sure, the crystals are deadly, but I was smuggling them legitimately, in a manner of speaking, for this doctor to experiment with. But—and this was the 'but' that was likely to deprive the System of my activities—even experimenting with them was illegal even if it needed to be done; also, I had promised not to rat on him before taking the job. Well, Casey Ritter may be a lot of things we won't mention, but he doesn't rat on his clients. So there I was, closeted with the ten members of the S.S. Customs Court, getting set to hear the gavel fall and the head man intone the sentence that would take me out of circulation for a long, long time. And instead, blast me, if they didn't foul me with this trip to good old Jupiter. I'd argued with 'em, but inside I'd been all set for the sentence, and even sort of reconciled to it. "Aw, hell, judge, that's just one of those screwy fairy tales! How could any—" The senior judge rapped ferociously, and I skidded to a halt. We possess well-authenticated photographs of these inhabitants, and if you are prepared to visit them and in some way worm from them the secret of their anti-gravity field, the government stands ready to issue you a full pardon as well as a substantial monetary reward. That whole Kooleen caper: Had it been just a trap to lead me straight to this? Not when I already had more counts against me than a cur has fleas. Well, a cross between a scorpion and a grasshopper, to be accurate. After all, in the pen a man can eat and breathe, and a guard won't reach in and nip off an arm or leg while he's got his back turned. Me, Casey Ritter, slickest slicker in the Solar System, led like a precious infant right where I'd flatly refused to go! "I just made a pass at the Killicut Emeralds, that's all, and got nabbed." Big as hen's eggs, an even dozen of 'em; and flawless, I'm a-shoutin', not a flaw!" Those emeralds were in the inner shrine of the super-sacred, super-secret temple of the cavern-dwelling tribe of Killicuts on Mars—the real aborigines.
 Never trust a crook
 Never give up on your friends  Never trust a crook  Always listen carefully to instructions  Don't judge others by how they look