The knuckles of the tall traveler knotted on his staff, but, like the others, he stepped aside to let the men in armor have the way. Among the motley and varied crowd he did not attract much attention in his drab, dusty garments. But once, as he passed a sword-seller's stall and the light that streamed from its wide door fell full upon him, he thought he felt an intense stare upon him, and turning quickly, saw a man in the brown jerkin of a free workman regarding him fixedly. This man turned away with undue haste, and vanished in the shifting throng. But Conan turned into a narrow by-street and quickened his pace. It might have been mere idle curiosity; but he could take no chances. The grim Iron Tower stood apart from the citadel, amid a maze of narrow streets and crowding houses where the meaner structures, appropriating a space from which the more fastidious shrank, had invaded a portion of the city ordinarily alien to them. The Tower was in reality a castle, an ancient, formidable pile of heavy stone and black iron, which had itself served as the citadel in an earlier, ruder century. Not a long distance from it, lost in a tangle of partly deserted tenements and warehouses, stood an ancient watchtower, so old and forgotten that it did not appear on the maps of the city for a hundred years back. Its original purpose had been forgotten, and nobody, of such as saw it at all, noticed that the apparently ancient lock which kept it from being appropriated as sleeping-quarters by beggars and thieves, was in reality comparatively new and extremely powerful, cunningly disguised into an appearance of rusty antiquity. Not half a dozen men in the kingdom had ever known the secret of that tower. No keyhole showed in the massive, green-crusted lock. But Conan's practised fingers, stealing over it, pressed here and there knobs invisible to the casual eye. The door silently opened inward and he entered solid blackness, pushing the door shut behind him. A light would have showed the tower empty, a bare, cylindrical shaft of massive stone. Groping in a corner with the sureness of familiarity, he found the projections for which he was feeling on a slab of the stone that composed the floor. Quickly he lifted it, and without hesitation lowered himself into the aperture beneath. His feet felt stone steps leading downward into what he knew was a narrow tunnel that ran straight toward the foundations of the Iron Tower, three streets away. The bell on the citadel, which tolled only at the midnight hour or for the death of a king, boomed suddenly. In a dimly lighted chamber in the Iron Tower a door opened and a form emerged into a corridor. The interior of the Tower was as forbidding as its external appearance. Its massive stone walls were rough, unadorned. The flags of the floor were worn deep by generations of faltering feet, and the vault of the ceiling was gloomy in the dim light of torches set in niches.