It was wrenched from his hands, its end snapped off and hurled spinning with terrific force. Then a grinding shriek of tormented metal, and the panzer's vast mass shook and wheeled half round in a storm of sand as the jammed tread stopped and slid. Almost before the machine had lurched to a full halt with a tremendous clank and rattle, Torcred had snatched up the broken end of his bar and was swarming up its side. In a moment he was perched atop it within easy reach of the single exit port, leaning against the smooth warm steel, feet braced solidly against the tread housing. A quick glance assured him that there were no vision slits giving a view of the panzer's back to those inside. He set himself and waited, controlling his labored breathing. The wait was not overlong. The panzer-men, seeing no attacker outside, but having heard their alarm and found their machine inexplicably crippled an instant later, had no choice but to come out and investigate. * * * * * The port-cover swung aside, and a man's crash-helmeted head and gray-clad shoulders emerged, back to Torcred. The Terrapin struck viciously and dented the helmet; almost before its top slid out of sight, he vaulted after it into the opening, disregarding the ladder. [Illustration: _Torcred struck viciously, denting the man's helmet._] He landed in a tangle of arms and legs--the man he had stunned sprawled atop another who struggled to free himself. Torcred sprang clear and, across the cramped central compartment of the panzer, faced a third gray-clad man with a drawn knife. Incredulity and fright were written large on the panzer-man's face. Out of sheer desperation he lunged forward in a stabbing rush; but he was no knife-fighter, and the two-foot length of steel in Torcred's hands was a far superior weapon. The knife flew wide and its wielder stumbled back, nursing a bruised forearm. Another figure appeared in the narrow door forward and stared at the scene with popping eyes--the driver, no doubt. Torcred greeting him with a ferocious grin and swung his club whistling back and forth. He looked and felt invincible. Then Ladna's voice behind him screamed, "Torcred! Look out!" He whirled, and the knife-blade gashed his shoulder instead of sinking into his back. Then Torcred struck a two-handed blow and felt bone give way beneath it. He took a couple of steps back from the crumpled body of the panzer-man who had unluckily disentangled himself from his unconscious comrade, and set his back against a solid bulkhead; on his face was still the savage grin that had frozen the driver in his tracks. The bird-girl dropped lightly from the ladder and came to his side, scooping up the knife that was red with Torcred's blood. Her shining eyes reflected his fierce elation of victory.