The dawn man returned by a different route, passing through the other edge of the city of the Ogrum. Here they found a heavy stone wall, like the retaining dike of a river. "Why wall, Guru?" Craig questioned. "Keep earth-shakers out of Ogrum squatting place," the dawn man answered. "Earth-shakers" was Guru's name for the dinosaurs and "squatting place" was his word for city. Beyond the wall was the vast swamp. The Ogrum had erected the wall to keep the dinosaurs out of their city. "Well, I'm damned," said Craig thoughtfully. "I wonder. Hurry, Guru. Must get back before sun rise." At a swift trot, the dawn man led him up the mountain. * * * * * "This is what we're going to do," Craig said excitedly to Michaelson. The sailors, listening closely, squatted around him in the darkness. Dawn was not far off. Already the sky in the east was beginning to turn gray. Swiftly he outlined his plan of attack, submitted it to the scientist. "I am no military strategist," Michaelson said slowly. "I am not competent to criticize your suggestions." "I am," a voice spoke. "I've studied military strategy. Your plan hasn't got a chance in a thousand to succeed. You are just getting us all killed for nothing." It was Voronoff who spoke. "That may be true," Craig admitted. "If you have a better plan, I'm willing to listen." "I've told you all along the only thing to do is to clear out of here as fast as we can." "That is the one thing we're not going to do," Craig said icily. "If you have nothing constructive to offer, keep your damned mouth shut." Voronoff sullenly walked away. Craig selected a group to charge the hangar where the planes were kept, a second group to provide a diversionary attack across the city, and a third group to hit the temple and release the prisoners. The attack was to start just after darkness fell the next night. At that time, so Guru said, all the Ogrum would be gathered in the temple to watch the sacrifice. "And after that," Michaelson said slowly. "What is to happen?" "Ah," said Craig. "There is the heart of the affair. What happens next will determine whether any of us ever get out of here alive. And," he looked steadily at the scientist, "that is where you come in." "I? What am I to do?" "You and Guru are going to take a dozen men and round up as many of Guru's people as you can find. Here is what you and Guru are going to do." In great detail Craig outlined the part the scientist and the dawn man were to play in the attack on the Ogrum. They made an odd pair. Michaelson, almost a physical weakling but possessed of one of the keenest minds of the Twentieth Century; Guru, a splendidly muscled giant but almost a child mentally. "Do--do you think our part in the attack will really work?" the scientist hesitantly asked. "It's got to work," Craig said bluntly. "If it doesn't work, we are all dead men." CHAPTER VII The Attack