But even before the question was asked, Kinnison's blackly invisible, indetectable speedster was well within the star cluster. The guardian fortresses were closer spaced by far than Helmuth's had been. Electromagnetics had a three hundred percent overlap; ether and subether alike were suffused with vibratory fields in which nullification of detection was impossible, and the observers were alert and keen. To what avail? The speedster was non-ferrous, intrinsically indetectable; the Lensman slipped through the net with ease. Sliding down the edge of the world's black shadow he felt for the expected thought-screen, found it, dropped cautiously through it, and poised there; observing during one whole rotation. This had been a fair, green world--once. It had had forests. It had once been peopled by intelligent, urban dwellers, who had had roads, works, and other evidences of advancement. But the cities had been melted down into vast lakes of lava and slag. Cold now for years, cracked, fissured, weathered; yet to Kinnison's probing sense they told tales of horror, revealed all too clearly the incredible ferocity and ruthlessness with which the conquerors had wiped out all the population of a world. What had been roads and works were jagged ravines and craters of destruction. The forests of the planet had been burned, again and again; only a few charred stumps remaining to mark where a few of the mightiest monarchs had stood. Except for the Boskonian base the planet was a scene of desolation and ravishment indescribable. "They'll pay for that, too, the fiends," Kinnison gritted, and directed his attention toward the base. Forbidding indeed it loomed; thrice a hundred square miles of massively banked offensive and defensive armament, with a central dome of such colossal mass as to dwarf even the stupendous fabrications surrounding it. Typical Boskonian layout, Kinnison thought, very much like Helmuth's Grand Base. Fully as large and as strong, or stronger--but he had cracked that one and he was pretty sure that he could crack this. Exploringly he sent out his sense of perception; nor was he surprised to find that the whole aggregation of structures was screened. He had not thought that it would be as easy as that! He did not need to get inside the dome this time, as he was not going to work directly upon the personnel. Inside the screen anywhere would do. But how to get there? The ground all around the thing was flat, as level as molten lava would cool, and every inch of it was bathed in the white glare of floodlights. They had observers, of course, and photo-cells, which were worse.