[Illustration: "NOT DER MOON OR BUST, BUT DER MOON UND BUST!"] "Und vhy then, you may vell ask, do I send you? Because der rocket may not attain eggscape velocity. Und in that case, it iss still an eggsperiment, budt a different vun. Der rocket, if it goes not to der moon, falls back on der earth, no? Und in that case certain instruments shall giff us further information than ve haff yet about things up there in space. Und you shall giff us information, by vether or not you are yet alife, vether der shock absorbers und vanes are sufficient in an earth-equivalent atmosphere. You see? "Then ladter, vhen ve send rockets to Venus maybe vhere an atmosphere eggsists, ve shall haff data to calculate the needed size of vanes und shock-absorbers, no? Und in either case, und vether or not you return, Mitkey, you shall be vamous! You shall be der virst liffing greature to go oudt beyond der stratosphere of der earth, out into space. "Mitkey, you shall be der Star-Mouse! I enfy you, Mitkey, und I only vish I vere your size, so I could go, too." Der tag, and the door to the compartment. "Gootbye, little Mitkey Mouse." Darkness. Silence. Noise! "Der rocket--if it goes not to der moon--falls back on der earth, no?" That was what the Herr Professor thought. But the best-laid plans of mice and men gang aft agley. Even star-mice. All because of Prxl. * * * * * The Herr Professor found himself very lonely. After having had Mitkey to talk to, soliloquies were somehow empty and adequate. There may be some who say that the company of a small gray mouse is a poor substitute for a wife; but others may disagree. And, anyway, the Professor had never had a wife, and he _had_ a mouse to talk to, so he missed one and, if he missed the other, he didn't know it. During the long night after the launching of the rocket, he had been very busy with his telescope, a sweet little eight-inch reflector, checking its course as it gathered momentum. The exhaust explosions made a tiny fluctuating point of light that was possible to follow, if one knew where to look. But the following day there seemed to be nothing to do, and he was too excited to sleep, although he tried. So he compromised by doing a spot of housekeeping, cleaning the pots and pans. It was while he was so engaged that he heard a series of frantic little squeaks and discovered that another small gray mouse, with shorter whiskers and a shorter tail than Mitkey, had walked into the wire-cage mousetrap. "Vell, vell," said the Professor, "vot haff ve here? Minnie? Iss it Minnie come to look for her Mitkey?" The Professor was not a biologist, but he happened to be right. It _was_ Minnie. Rather, it was Mitkey's mate, so the name was appropriate. What strange vagary of mind had induced her to walk into an unbaited trap, the Professor neither knew nor cared, but he was delighted. He promptly remedied the lack of bait by pushing a sizable piece of cheese through the bars.