Just as she was about to let go, Steve reached her and held on to her with his free hand. Then his father lent his help and Sue was safe. She sobbed for a moment from the fright she had had and Mr. Shannon suggested that they go back to the rim where they would be safe again. Both children agreed, for they had suddenly lost all interest in the hub. By the time they got to the Weather Control Bureau they found more worry awaiting them. Men were hustling about the huge room with serious looks on their faces. One of them was looking into the eyepiece of a large machine that was pointed out the window down onto Earth. “What’s wrong?” Mr. Shannon asked one of the men. “A tornado is headed for Little Rock, Arkansas!” was the shocking reply. “I hope our missile scores a hit, but it isn’t going to be easy because the Wheel has already moved past the United States!” “The missile’s _got_ to hit!” Steve burst out. “Our home and Mom are there!” “Yes, it’s simply _got_ to!” Sue added tearfully. The Shannons had to stand helplessly on the side as the tornado fighters went to work. The missile gun was in another part of the Wheel, but the orders for firing it would leave this room by radio. “Oh, why couldn’t Mom have come with us?” Sue asked. “She would have been safe here!” Steve felt his whole body tensing like a wound spring. The perspiration was beading his forehead and his knees were weak. On his father’s face there was a dark look and Steve saw that his big hands were opening and closing. “Twenty seconds to go before firing,” the man at the machine said slowly over the radio mike on his chest. “Steady. Eighteen—seventeen—” “Why don’t they hurry?” Sue cried. “They’re so slow!” “They have to do it a certain way,” Mr. Shannon answered. “They know what they’re doing, Honey. Don’t be afraid.” But she _was_ afraid. And so was Steve. And her father, too. Everyone in the room was afraid because no one could say whether the tornado could be destroyed before it hit the city or not. “Eight—seven—six—” droned the unhurried voice of the operator. The Shannons hardly dared breathe for fear of disturbing the man at the machine. Steve felt Sue’s body quivering next to him. It seemed as if the seconds were dragging on endlessly. “Three—two—one—FIRE!” Steve felt nothing but he knew the tornado bomb was on its way, speeding hundreds of miles a second Earthward. For long, awfully long, moments after the operator had said, “Fire!” the Shannons waited for him to speak again. He kept looking calmly through the eyepiece of the machine as though just studying the stars. Then at last they saw a smile spread over his face and he said to everyone in the room, “It’s a hit! Little Rock is safe!” [Illustration: _The tornado bomb was on its way, speeding hundreds of miles a second Earthward_] Sue and Steve whooped as if it were Christmas morning. Where a minute before they had been greatly worried, now they were happy as they never believed they could be.