After an interval, the length of which he did not know, Victor Nelson opened his eyes slowly, for his head throbbed like a savage's war drum. Uttering a stifled groan he shut the lids to still an overpowering sense of nausea which gripped him, but a moment later he made another attempt to discover in what sort of place he found himself. Gradually, his eyes became accustomed to a curious orange-red glare beyond a series of bars. Bars? The idea fixed itself in his benumbed brain; bars meant prison! Yes, those grim blank walls bore out the assumption. He lay on the damp stone floor of what must be a fairly spacious cell. Beneath his leather aviator's jacket he shuddered. "Jail, eh? What a nice place to wake up in!" A groan from behind him prompted Nelson to painfully raise his head and look about. He blinked dazedly, meanwhile trying to focus his eyes, then he heaved a faint sigh of relief as his gaze encountered the muscular, well-proportioned figure of Richard Alden, who half sat, half reclined, against one of the grey stone walls, burying a ghastly pale face between trembling hands. "You hurt?" To speak, Nelson drew a slightly deeper breath and at once became conscious of a horrible, throat-wrenching stench. Dimly, he recalled having once before encountered such an odor; when was it? Oh, yes; during the Great War when he'd stumbled into a dugout tenanted by long unburied corpses. A cold finger stabbed at his brain. Corpses. "Are you hurt, Dick?" he repeated hoarsely. * * * * * The lax figure stirred and Alden's blonde head was raised slowly. "I don't know." His voice came very thickly. "I--I'm still dizzy. What's happened?" "Damned if I know; but those bright boys have evidently heaved us into a calaboose of some kind!" Nelson, on peering about, had discovered that one end of the cell was closed only by a series of massive bronze bars; the two other walls were solid masonry; while the fourth was also solid but fitted with a small oval door of bronze. "Calaboose? The hell you say!" Alden coughed feebly. "My God, but that steam was terrible stuff. I nearly smothered before I got knocked out." Slowly, the younger aviator looked about, and suddenly his eyes widened in an expression of indescribable horror. "Look!" Alden's voice had died to a shaken whisper. "My God, Nelson, we're finished! Look at that allosaurus!" * * * * *