Just then the view lit up and the bristles along Pupsie's back suddenly stood on end. The scene in the viewplate was familiar. Six ratcatchers were lined up, one behind another, with the foremost pointing the Colt at his own midriff. Through the adjoining wall, which was transparent on the viewplate, a man in the uniform of the chief rat of the ratcatchers, was visible holding his fingers in his ears and with a terrified and painful expression on his face. The blonde woman jumped when the bang sounded and the six ratcatchers reeled and then collapsed. The chief beyond the wall looked a trifle relieved to find himself still alive, but Zitts snorted with audible disgust. "Bunglers!" Zitts growled, then looked at Pupsie. "That weapon, Pupsie," he said. "Get a good whiff of it." The huge nostrils flared and sniffed in a way that stirred a strong breeze in the room and sent prickles along the blonde woman's spine. Then Pupsie looked up and winked. "Now trace it to the murderer," Zitts ordered. Pupsie gathered himself for a leap at the chief rat, but Zoo sprang between him and the viewplate and shut off the machine. "No, no," Zitts cautioned. "His smell is on the weapon, of course. But he merely examined it. Use your head now and tune in the machine yourself and find the murderer." Nodding, Pupsie moved close to the machine, switched it on and began tuning radarlike by sniffing and twisting the dials. Almost at once his eyes lighted and his tongue lolled out and his muscles stiffened for action. The blonde woman held her breath, expecting to view the murderer. The view lit up faintly, became brighter, became a dark alley with a cat inspecting a garbage pail. "No, no!" Zitts cautioned. "This is no time for sport. Get down to business." Pupsie continued tuning and suddenly began panting and gasping and twitching in every muscle. Recognizing the emergency, Zitts thundered "The treadmill, Zoo!" * * * * * Zoo stamped on the floor and started an endless carpet moving under Pupsie's feet. It was just in time, for Pupsie was running like the very devil in order to remain in the same place. He was in pursuit of a female dog which appeared on the viewplate. Features darkening and eyes blazing, Zitts waited for Zoo to turn off the machine. Then in a thunderously quiet voice he called Pupsie to book. "I warned you this is no time for sport!" Zitts glanced at Zoo who produced a dogcatcher's net and held it threateningly above Pupsie. The poor dog shuddered. "For the last time," Zitts said ominously, "I'm warning you." The blonde woman felt so sorry for the creature she turned tearful eyes to Zitts in mute appeal. Zitts appeared to relent. "When you find that murderer," he said, temporizing, "I shall order you a special nine-foot bone from one of those Martian tyrannasauraplexus creatures. Now, keep your mind on your work!"