 What are two kinds of goods Casey Ritter deals with throughout the story?
It just ain't big enough for a gent of scope and talent; and the day the Solar System Customs caught me red-handed smuggling Kooleen crystals in from Mars, I knew I was in that corner, and sewed up tight. 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. Insect-like creatures who manifestly migrated there from some other system and who inhabit the Red Spot of the planet, floating in some kind of artificial anti-gravity field in the gaseous portion of the atmosphere—" I snorted. 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. Your talents, Mr. Ritter, seem, shall we say, eminently suited to the task." 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. No doubt they had it figured that I'd gratefully throw myself into a sea of ammonia among man-size scorpions just for the hell of it. 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. The way that bunch of stuffed shirts in the S.S.C. made a gold-barred chimpanzee out of me has broken my spirit and turned me into an honest trader. "I just made a pass at the Killicut Emeralds, that's all, and got nabbed." "What were you trying to do, start a feud between us and Mars?" 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.
 Killicut Emeralds and Kooleen Crystals
 Strychnine and Space suits  Jupiter crystals and Mars emeralds  Kooleen Crystals and Kooleen Emeralds  Killicut Emeralds and Kooleen Crystals