Sir Austin was in his element. Indeed, he was in the seventh heaven of rapture as he observed, recorded, and calculated. He chuckled over his interferometers, he clucked over his meters, now and again he emitted shrill whoops of triumph as a particularly abstruse bit of knowledge was torn from its lair. He strutted, he gloated, he practically purred as he recorded upon the tape still another momentous conclusion or a gravid equation, each couched in terms of such incomprehensibly formidable mathematics that no one not a member of the Conference of Scientists could even dimly perceive its meaning. Cardynge finished his work; and, after doing everything that could be done to insure the safe return to Science of his priceless records, he simply preened himself. He wasn't like an old hen, after all, Kinnison decided. More like a lean, gray tomcat. One that has just eaten the canary and, contemplatively smoothing his whiskers, is full of pleasant, if somewhat sanguine visions of what he is going to do to those other felines at that next meeting. Time wore on. A long time? Or a short? Who could tell? What possible measure of that unknown and intrinsically unknowable concept exists or can exist in that fantastic region of--hyperspace? Interspace? Pseudospace? Call it what you like. * * * * * Time, as has been said, wore on. The ships arrived at the enemy base, the landing signal was given. Worsel, on duty at the time, recognized it for what it was--with his brain that was a foregone conclusion. He threw the switches, then flew and wriggled as even he had never done before, hurling a thought as he came. And as the Velantian, himself in the throes of weird deceleration, tore through the thinning atmosphere, the queasy Gray Lensman watched the development about them of a forbiddingly inimical scene. They were materializing upon a landing field of sorts, a smooth and level expanse of black igneous rock. Two suns, one hot and close, one pale and distant, cast the impenetrable shadows so characteristic of an airless world. Dwarfed by distance, but still massively, craggily tremendous, there loomed the encircling rampart of the volcanic crater upon whose floor the fortress lay. And what a fortress! New--raw--crude--but fanged with armament of might. There was the typically Boskonian dome of control, there were powerful ships of war in their cradles, there beside the _Dauntless_ was very evidently the power plant in which was generated the cryptic force which made interdimensional transit an actuality. But, and here was the saving factor which the Lensman had dared only half hope to find, those ultrapowerful defensive mechanisms were mounted to resist attack from without, not from within. It had not occurred to the foe, even as a possibility, that the Patrol might come upon them in panoply of war through their own hyperspatial tube!