Isobar knew all about the Grannies. The only mobile form of life found by space-questing man on Earth's satellite, their name was an abbreviation of the descriptive one applied to them by the first Lunar exployers: Granitebacks. This was no exaggeration; if anything, it was an understatement. For the Grannies, though possessed of certain low intelligence, had quickly proven themselves a deadly, unyielding and implacable foe. Worse yet, they were an enemy almost indestructible! No man had ever yet brought to Earth laboratories the carcass of a Grannie; science was completely baffled in its endeavors to explain the composition of Graniteback physiology--but it was known, from bitter experience, that the carapace or exoskeleton of the Grannies was formed of something harder than steel, diamond, or battleplate! This flesh could be penetrated by no weapon known to man; neither by steel nor flame, by electronic nor ionic wave, nor by the lethal, newly discovered atomo-needle dispenser. All this Isobar knew about the Grannies. Yet: "They ain't been any Grannies seen around the Dome," he said, "for a 'coon's age. Anyhow, if I seen any comin', I could run right back inside--" "No!" said Commander Eagan flatly. "Absolutely, _no_! I have no time for such nonsense. You know the orders--obey them! And now, gentlemen, good afternoon!" He left. Sparks turned to Isobar, grinning. "Well," he said, "one man's fish--hey, Jonesy? Too bad you can't play your doodlesack any more, but frankly, I'm just as glad. Of all the awful screeching wails--" But Isobar Jones, generally mild and gentle, was now in a perfect fury. His pale eyes blazed, he stomped his foot on the floor, and from his lips poured a stream of such angry invective that Riley looked startled. Words that, to Isobar, were the utter dregs of violent profanity. "Oh, dagnab it!" fumed Isobar Jones. "Oh, tarnation and dingbust! Oh--_fiddlesticks_!" II "And so," chuckled Riley, "he left, bubbling like a kettle on a red-hot oven. But, boy! was he ever mad! Just about ready to bust, he was." Some minutes had passed since Isobar had left; Riley was talking to Dr. Loesch, head of the Dome's Physics Research Division. The older man nodded commiseratingly. "It is funny, yes," he agreed, "but at the same time it is not altogether amusing. I feel sorry for him. He is a very unhappy man, our poor Isobar." "Yeah, I know," said Riley, "but, hell, we all get a little bit homesick now and then. He ought to learn to--" "Excuse me, my boy," interrupted the aged physicist, his voice gentle, "it is not mere homesickness that troubles our friend. It is something deeper, much more vital and serious. It is what my people call: _weltschmertz_. There is no accurate translation in English. It means 'world sickness,' or better, 'world weariness'--something like that but intensified a thousandfold.