A ship had two doors, the inside one and one opening outside the hull. Between the two was a narrow air space. It was used as an air lock in which one could return to normal pressure before entering the ship from some thin-aired world. If you put a man in there and turned the pressure wide open-- "This makes even a Venusian talk," the big patrolman told Hudson and Leggett. "When the pressure gets up around two hundred and their ear drums start cracking, they get mighty conversational." When the patrolman who had gone into the police plane returned, he held the door open and the pistol in Flint's side pushed him toward it. But at the door, the radio stopped them. The lawyer had left the speaker on. "_Calling Saturn Relay Station. Relay to Earth, to K. V. Vaun Fur Fashions, Inc., New York City. Message as follows: Miss Vaun has been kidnapped. She is held for one million dollars ransom. Forward to Saturn by tonight's Space Express one million dollars in raw platinum. Saturn Express Agency will be informed later how to deliver it. End of message._" The big patrolman turned to Flint standing beside the door. "Pretty smart, except that it didn't work." Then to the fellow holding the pistol at Flint's back: "Throw him in and squirt the air. I'll call Saturn and tell 'em to forget that relay message." But once again the radio stopped them. "_Look! At the door!_" The voice was sharp and high. It was Karen Vaun's. "_Keep still! Don't let it hear us!_" Greeno again. "What in hell--" the patrolman breathed. "_It's reaching in!_" Karen's voice, a terrified whisper. "_Look out for its claws!_" Two explosions rang out--Greeno's old bullet gun; he didn't have an ice pistol. Greeno yelled "_Get back!_" There was fright in even his mechanical voice as a dull crash merged with his words. Then there was instant silence. Something had smashed Greeno's radio set. "It's the bat!" Flint said. "It's got them cornered! We've got to get out there!" Somehow, now, the thought of that thing reaching into the door, clawing at Karen Vaun, pressed back against the wall, made him forget all about his plans for capturing the bat, forget he was under arrest for kidnapping. "Let's go--I'll take you to them!" "It's another of his tricks," one of the patrolmen said. "Trying to lead us into a trap of some kind." "Listen, you stupid fools," Flint almost yelled, "don't you understand? That bat's out there. They haven't a rabbit's chance. We haven't got time to talk about it." The big fellow winked at the others. "If it's a space bat," he said, "we'll need help. I'll call for some of the boys to go with us, with some bigger guns--for the bat or for any little ambush you might have planned."