"These Connies are plenty smart. I don’t like leaving you unprotected, even within reach of Mercury and Terra, but orders are orders. Keep the snapper-boat and you’ll at least be able to put up a fight if you bump into trouble." The asteroid sped on its lonely way for two days and then a cruiser came out of space, its nuclear drive glowing. The Planeteers manned the rocket launcher and Rip and Santos stood by the snapper-boat just in case, but the cruiser was the _Sagittarius_, out of Mercury. Captain Go Sian-tek, a Chinese Planeteer officer, arrived in one of the cruiser’s landing boats accompanied by three enlisted Planeteers. They were all from the Special Order Squadron on Mercury. Captain Go greeted Rip and his men, then handed over a plastic stylus plate ordering Rip to deliver six cubic meters of thorium for use on Mercury. While Koa supervised the cutting of the block, Rip and the captain chatted. The Mercurian Planeteer base was in the twilight zone, but the Planeteers did all their work on the sun side, using special alloy suits to mine the precious nuclite that only the hot planet provided. At some time during its first years, Mercury had been so close to the sun that its temperature was driven high enough to permit a subatomic thermo-nuclear reaction. The reaction had shorn some elements of their electrons and left a thin coating of material composed almost entirely of neutrons. The nuclite was incredibly dense. It could be handled only in low gravity because of its weight. But nothing else provided the shielding against radiation and meteors half so well and it was in great demand for spaceship skins. "Things aren’t so bad," Go told Rip. "The base is comfortable and we only work a two hour shift out of each ten. We’ve had a plague of silly dillies recently. They got into one man’s suit while we were working, but mostly they’re just a nuisance." Rip had heard of the creatures. They were like earth armadillos, except that they were silicon animals and not carbon like those of earth. They were drawn to oxygen like iron to a magnet, and their diamond hard tongues, used for drilling rock in order to get the minerals on which they lived, could drive right through a space suit. Or, if they could work undetected for a short while, they could drill through the shell of a space station. _Scralabus primus_ was the scientific name of the creature, but the fact that it looked like a silicon armadillo had given it the popular name of "silly dilly." Apart from its desire for oxygen it was harmless. Koa reported, "Sir, the block of thorium is ready. We’ve hung it on a line behind the landing boat. The blast won’t hurt it, and it’s too big to get inside the boat." "Fine, Koa. Well, Captain, that does it."