On and on they went. A bicycle policeman shouted at them as they whizzed by and, clambering on his machine, started in pursuit. They passed a crowded trolley car, and the passengers stared at their mad speed. They reached the outskirts of Georgetown and the more open country beyond. They gained on the car ahead of them, and Brett shouted aloud with the joy of the chase as they drew nearer. They passed the Naval Observatory, cut across Massachusetts Avenue extended, just shaving several other automobiles, the startled drivers thereof wasting their breath in sending endless curses after them. They swept past the Cathedral Close and continued their race along the Rockville pike. As they approached the River Road they saw Thornton turn his car, scarcely reducing his speed, and cut across the road. It was a dangerous corner at any time, and as the front wheels made the turn the body of the car slued around. There was a grinding, splintering crash as the car struck one of the tall poles supporting the overhead trolley wires, and the big machine turned turtle. Brett's chauffeur put on a final burst of speed, and the limousine leaped madly down the road. A cry of horror broke from the three men as a tongue of flame shot up from the overturned car ahead of them. "By Heavens! the gasolene has ignited!" gasped Douglas. He was on the running board when the car slowed down near Thornton's motor. The latter was a mass of flames. Douglas sprang to the ground, and the others followed him. "Get some fence rails," he directed. "We must try and lift the car so that Thornton can crawl out." In a few minutes the men were back with boards torn from a nearby fence, but in that short time the flames had gained headway, and they were driven back by the intense heat. Unfortunately there was no loose sand at hand. An outgoing trolley car stopped, and several passengers ran to Douglas' aid. The fence boards caught fire and had to be put out, but finally the car was raised a slight distance from the ground, and a cry of exultation broke from the toiling men, only to die into a groan as a sharp explosion, followed by a heavier detonation, rang out. Dropping their hold on the boards, the men bolted to a safe distance down the road. "It's hopeless!" gasped Brett. "No man can live in that fiery furnace." Douglas groaned aloud. He had been shocked beyond measure by the discovery of Thornton's guilt and treachery, for he had liked him, and had accepted his hospitality. It was horrible to see him meet such a fate. Better the electric chair than being roasted alive. "Perhaps he jumped from the car before it turned turtle," he suggested. "It's hardly likely," exclaimed Brett dubiously. "Still, we might look along the road. We can do no good over there." He shuddered slightly as he turned to look at the still burning car. The steel and metal work had been twisted into grotesque shapes by the great heat, which added to the ghastly picture.