The first small opening appeared directly in line between the muzzle of Kinnison's rifle and one of the guns of the enemy, and in the moment of its appearance the Patrolman's weapon began its stuttering, shattering roar. The Boskonians had seen the hot spot upon the wall, had known instantly what it meant, and were working frantically to swing their gun mounts around so as to interpose their dureum shields and to bring their own rifles to bear. They had almost succeeded. Kinnison caught just the bulge of one suit of armor in his sights, but that was enough. The kinetic energy of the stream of metal tore him out of the saddle; he was literally riddled while still in air. Two savage bursts took care of the semiportables and their operators--as has been intimated, the shields of the semis were not designed to withstand the type of artillery Kinnison was using. That made it cannon to cannon, one to one; and the Lensman knew that those two identical rifles could hammer at each other's defenses for an hour without doing any serious damage. He had, however, one big advantage. Being closer to the bulkhead he could depress his line of fire more than could the Boskonian. He did so, aiming at the clamps, which were not built to take very much of that sort of punishment. One front clamp let go, then the other, and the Lensman knew what to do about the rear pair, which he could not reach. He directed his fire against the upper edge of the dureum plate. Under the awful thrust of that terrific storm of steel the useless front clamps lifted from the floor. The gun mount, restrained from sliding by the unbreakable grip of the rear clamps, reared up. Over it went, straight backward, exposing the gunner to the full blast of Kinnison's fire. That, definitely, was that. * * * * * Kathryn heaved a sigh of relief; as far as she could "see", the tube was still empty. "That's my Pop!" she applauded inaudibly to herself. "Now," she breathed, "if the darling has just got jets enough to figure out what may be coming at him down this tube--and sense enough to run back home before it can catch him!" Kinnison had no suspicion at all that any danger to himself might lie within the tube. He had no desire, however, to land alone in a strange and possibly half-crippled enemy ship in the exact center of an enemy base, and no intention whatever of doing so. Moreover, he had once come altogether too close to permanent immolation in a foreign space because of the discontinuance of a hyperspatial tube while he was in it, and once was once too many. Also, he had just got done leading with his chin, and once of that, too, was once too many. Therefore, his sole thought was to get back into his own space as fast as he could get there, so as soon as the opposition was silenced he hurried into the control room and reversed the vessel's drive.