The slight man in guardsman's blue glanced over his shoulder and vanished abruptly into the circular lock. His companion wheeled on the topmost step, looking down with some irritation on his unhandsome face, but with no apparent doubt of his command of the situation. "Yes?" he inquired frostily. "What goes on here?" snapped the guard, frowning at the tall figure silhouetted against the glow in the airlock. "The crew's signaled all aboard and the ship lifts in two minutes. You ought to be--" "I am Semul Mury, Poligerent for the City of Dynamopolis," interrupted the tall man with asperity. "The City is naturally interested in the delivery of the power which will revivify our industries." He paused, sighed, shifting his weight to the next lower step of the gangway. "I suppose you'll want to re-check my credentials?" The guard was somewhat confused; a Poligerent, in ninth-century bureaucracy, was a force to be reckoned with. But he contrived to nod with an appearance of brusqueness. Fully expecting official papers, signed and garnished with all the pompous seals of a chartered metropolis, the guard was dazed to receive instead a terrific left-handed foul to the pit of the stomach, and as he reeled dizzily, retching and clawing for his gun, to find that gun no longer holstered but in the hand of the self-styled Poligerent, pointing at its licensed owner. "I think," Mury said quietly, flexing his left wrist with care the while his right held the gun steady, "that you'd better come aboard with us." The guard was not more cowardly than the run of politically-appointed civic guardsmen. But a flame gun kills more frightfully than the ancient electric chair. He complied, grasping the railing with both hands as he stumbled before Mury up the gangway--for he was still very sick indeed, wholly apart from his bewilderment, which was enormous. Above, Ryd Randl waited in the lock, flattened against the curved wall, white and jittering. The inner door was shut, an impenetrable countersunk mirror of metal. "Cover him, Ryd," ordered Mury flatly. In obedience Ryd lugged out the heavy flame pistol and pointed it; his finger was dangerously tremulous on the firing lever. He moistened his lips to voice his fears; but Mury, pocketing the other gun, threw the three-way switch on the side panel, the switch that should have controlled the inner lock. Nothing happened. "Oh, God. We're caught. We're trapped!" The outer gangway had slid up, the lock wheezed shut, forming an impenetrable crypt of niosteel. * * * * * Mury smiled with supernal calm. "We won't be here long," he said. Then, to quiet Ryd's fears, he went on: "The central control panel and the three local switches inside, between, and outside the locks are on the circuit in that order. Unless the locks were closed from the switch just beyond the inner lock, that lock will open when the central control panel is cut out in preparation for lifting."