The door in the back of the lock clanked open. Joe tried to walk toward it. He discovered his astounding clumsiness. To walk in magnetic-soled shoes in weightlessness requires a knack. When Joe lifted one foot and tried to swing the other forward, his body tried to pivot. When he lifted his right foot, he had to turn his left slightly inward. His arms tried to float absurdly upward. When he was in motion and essayed to pause, his whole body tended to continue forward with a sedate toppling motion that brought him down flat on his face. He had to put one foot forward to check himself. He seemed to have no sense of balance. When he stood still--his stomach queasy because of weightlessness--he found himself tilting undignifiedly forward or back--or, with equal unpredictability, sidewise. He would have to learn an entirely new method of walking. A man came in the lock, and Joe knew who it was. Sanford, the senior scientist of the Platform's crew. Joe had seen him often enough on the television screen in the Communications Room at the Shed. Now Sanford looked nerve-racked, but his eyes were bright and his expression sardonic. "My compliments," he said, his voice tight with irony, "for a splendidly futile job well done! You've got your cargo invoice?" Joe nodded. Sanford held out his hand. Joe fumbled in his pocket and brought out the yellow sheet. "I'd like to introduce my crew," said Joe. "This is Haney, and Chief Bender, and Mike Scandia." He waved his hand, and his whole body wobbled unexpectedly. "We'll know each other!" said Sanford sardonically. "Our first job is more futility--to get the guided missiles you've brought us into the launching tubes. A lot of good they'll do!" A huge plate in the roof of the lock--but it was not up or down or in any particular direction--withdrew itself. A man floated through the opening and landed on the ship's hull; another man followed him. "Chief," said Joe, "and Haney. Will you open the cargo doors?" The two swaying figures moved to obey, though with erratic clumsiness. Sanford called sharply: "Don't touch the hull without gloves! If it isn't nearly red-hot from the sunlight, it'll be below zero from shadow!" Joe realized, then, the temperature effects the skin on his face noticed. A part of the spaceship's hull gave off heat like that of a panel heating installation. Another part imparted a chill. Sanford said unpleasantly, "You want to report your heroism, eh? Come along!" He clanked to the doorway by which he had entered. Joe followed, and Mike after him. They went out of the lock. Sanford suddenly peeled off his metal-soled slippers, put them in his pocket, and dived casually into a four-foot metal tube. He drifted smoothly away along the lighted bore, not touching the sidewalls. He moved in the manner of a dream, when one floats with infinite ease and precision in any direction one chooses.