"Air?" It compressed its lips. "Ah, I remember air. A substance needed on Earth for life. We never understood it." "Don't you breathe?" asked Pink. "Don't you take any element into your system and mix it with your blood and then--oh, you haven't any blood." He paused. "But don't you need _any_ outside element to sustain life?" "No. Nor do we eat." "But you are organic life?" "Of course. A life which you cannot understand, I see. A life impervious to anything beyond it, indestructible and eternal." _I think you're lying_, said Pink to himself. Nothing in the universe is indestructible ... or at any rate, unalterable. Everything has its Achilles heel, even the atom. * * * * * The monster spoke, half to itself. "That, the locked switch was the air, then. I thought it was the air-lock." It laughed. Pink thought it had a pretty primitive sense of humor. "Not the air-lock, but the air." "You wanted to let your friends into the ship," accused Pink. The beast nodded. "Didn't you know that opening the air-locks without sealing off their compression rooms would kill all the humans aboard?" "No," it said. "I want you alive. Some of you. To teach us the working of this rocket." "Spaceship," corrected Pink without thinking. Then, "Why do you want the ship?" Its eyes glowed fire at him. "To return to Earth," it hissed. "To return to our own planet!" "_Your_ planet!" "As much as yours, mortal." It leaned forward, obscuring practically all the room for him. "Show me how to open the air-locks," it said. "In a swine's eye." "With safety to yourself, naturally," it said impatiently, "Come, show me." "Find the machinery yourself. Experiment. Knock us all off. You'll be stuck out here with a ship you can't operate." It plucked him off the foam-couch and hurled him against the wall, jarring him in every bone. "Show me how," it roared. "Thou zed, thou cream-faced loon--" Shakespeare? wondered Pink--"show me the controls!" Pink dived behind a stationary chair. He drew his useless pistol and threw it at the being's face; it rebounded to the floor. He snatched up a vase of ever-blooming Jovian lilies, sent them after the gun. The monster reached for him, snarling. He leaped over its hand, hurdling it as if he were a boy crossing a fence. On the far wall were many weapons. When he made Captain, and was given the _Elephant's Child_ as his flagship, he had transferred all his belongings to it, so that nowhere in the galaxies would he ever feel at home save here. Among his keepsakes was the collection of antique weaponry handed down to him by his father, whose grandfather had bought them in the long ago from many museums. Gradually he had added to the collection, souvenirs of the planets he had explored. They were bracketed on the wall. Zulu war clubs and Kentucky muskets. Martian spear-guns and antiquated jet-pistols; a Derringer, a Colt .44, a blowpipe from an unknown Pacific island.