I chuckled when I saw the space-suited cat--for so I thought of it. It was cat-size, in a little form-fitting spacesuit, and it scampered after its master on four legs, space-suited tail wagging behind. It was sort of a cute little thing, I thought; no wonder its master didn't care to leave it behind. "Everything all set?" I asked. "Transfer is completed," said the captain of the other ship. He closed his lock, and pulled away from us. "Close the lock!" I ordered. I gestured to a crewman standing by. "Show the Ambassador to his room," I said. When the Ambassador and his pet were in their special fluorinated stateroom I called them on the special television hookup I had set up between them. They had taken their spacesuits off and were lying sprawled out in their green murky atmosphere, the Ambassador in his bunk and the pet in his. I could hardly see into the room over my circuit but I could see that the Ambassador was very human and that the pet was pretty much like a cat, except that he had sharp-clawed fingers instead of the soft little pads a cat has. "Everything all right in there?" I asked. "Fine, just fine. How long will it take to get to Earth?" "About three weeks," I said. "We'll be going into warp any minute." "Very well," came the reply. * * * * * I didn't expect to have many dealings with the Ambassador. I had been told that he would have his own food supply and naturally he was confined to his fluorinated stateroom. So we settled down to a pleasant return trip. But on the second day of warp I was awakened from sweet dreams by Whitey Durbin, the Night Engineer. He shoved me around in my bunk until I opened one eye and said "Whatsamatter?" "It's the cat, Chief!" "Cat? What cat? You crazy, Whitey? Lemme go back to sleep." But he was obstinate. "The Ambassador's pet. It's out of its room." "Huh? But it can't breathe--" "It's wearing a spacesuit. And it's wandering all over the ship, snooping around. I caught it in the drive section and up front with the charts. I don't like it, Chief." "No. Neither do I." I was wide awake all at once. There had been something fishy about this pet business all along and now I was suspicious. Suppose the pet were a little smarter than a cat? Suppose it was snooping around innocently enough--and actually soaking up vital secret information about the workings of a Terran spaceship? But I didn't know what to do. My orders stressed the fact that I had to handle the Ambassador with kid gloves--but on the other hand, was I supposed to let that creature roam all over the ship? "Get me a hookup with Home Base," I said. "And in the meantime keep an eye on that cat. Don't let it catch wise but try to follow it around. And _don't_ stop it from roaming. These aliens may be touchy about the funniest things." I got in touch with Home Base in jig time. Commander Mahoney was the man I spoke to. "How's that Ambassador, Martin?"