Biff pointed the pusher away from the freighter. Steve saw a burst of fire beside them and the three of them sped off toward the big ship. As Sue reached the platform, her father was there to help her aboard. She could see in his eyes the fear he had felt for them. Steve was surprised to have the crew greet him warmly with pats on the back. The boy turned to his father. “Why are they calling me a hero?” he asked. “It was Biff who saved us!” “Not taking credit away from Biff, any good spaceman would have done what he did,” said Mr. Shannon. “But few would have attempted your trick of jumping into space after your sister with no way of getting back. Right, Biff?” Biff nodded his plastic helmet. “It wasn’t the smartest thing you could have done, Steve, but it showed your bravery. Courage counts just as much as ability in a spaceman. Don’t ever forget that, son.” Steve, who wanted to be a spaceman some day, would not forget it. _THE FLYING MOUNTAIN_ Steve and Sue were playing a game as the freighter headed through space toward Earth. It was fun trying to see who could build the higher tower of sticks. The young Shannons were in extra good spirits. Before long they would be seeing Mom and their home in Arkansas, after being in space for so many months. Steve carefully placed the last stick on his tower which was almost as high as he could reach. “_I_ won, Sis!” he exclaimed. But as he drew his hand away, it brushed against the tower, causing the sticks to drift off in all directions. “_I_ won!” Sue cried gleefully, “Yours broke up!” Steve made a face and began picking the sticks out of the air before they floated too far. It was lack of weight in space that made it possible to play such a game. The twins would have hung in the air like the sticks if their shoe soles were not held to the floor by magnetism. “I’ll beat you next time,” Steve boasted. Before they could start again, their father came into the room. “It looks as though we may not be getting home as quickly as we had expected, kids. Captain Furman has received an S. O. S. from a passenger rocket that’s down on the asteroid, Sierra.” The twins knew an asteroid to be one of the thousands of tiny planets in the Solar System. “Are we going to her aid?” Steve asked. “It depends on whether we have enough fuel or not,” his father replied. “Even atomic fuel runs out sometime, you know. Captain Furman is talking with his officers now. It’ll be a shame if we can’t help the _Pole Star_—as much as I want to see Mom.” It was just like his unselfish dad to say that, Steve thought. He felt the same way about it. And he didn’t doubt that tender-hearted Sue was of the same mind. Mr. Shannon started out of the room again. “I’m going to see what they are going to do.” Steve and Sue went back to their game. But somehow it wasn’t as much fun now. People were in trouble and trouble in space was often a frightening thing.