The guard ship on the outer end of the Asteroid Tunnel was anchored in space a short distance from the tunnel itself. It had to carry its own supplies, heavy armament and ammunition. Normally, it was capable of holding off a dozen space fighters, sending them reeling back with the heavy punches from its cannon. The Warrior Patrol came in on a sweeping arc, and slowed to circle about and finally hide the rugged, stocky mother-ship that guarded the tunnel. Orders were given. Ships and pilots were warned not to fly too close to the heaving mass of asteroids. They looked solid. Actually, they were in motion every second, tons of ragged, grinding metal and stone, heaving a few inches this way or that, destroying anything that touched their surface. It was through this terrifying belt of death that Blair Freedman had first dared point the prow of the "Cutter" and had, by sheer guts, torn a tunnel through the asteroids that served to demolish the thousands of miles of impossible flying by the outside route to Parma. In peace, the asteroid belt had been pierced by the needle-like tunnel and through it commerce poured to the other worlds. It was the Panama Canal of space. In peace time, a simple job of patrolling. In war, it might become a hell-spot of intrigue and battle. The Warrior Patrol had come to protect it, keep it open, and to prevent the fighting ships of Vestena from using it to conquer Parma. A vast set for a chess game. The pieces were placed, alert and waiting, about the tunnel head. When would the opposing player make his first move? Lieutenant Blair Freedman left his ship, moved carefully up the deck of the mother-ship and entered the air lock. In five minutes he was talking to fat, easy going Captain Stew in the mother-ship. Captain Stew wasn't the pudgy old gentleman's real name, but he had been called by it for so many years that any other he may have had was long forgotten. The Captain, with his home-made, blue denim uniform and enormous black pipe, led Freedman into his cabin and offered him the place of honor on his bunk. "Sit, Blair," he said. "Suppose you heard the news?" Freedman nodded. He hated to ask what had happened. Captain Stew was a tough old warrior. He could hold off half an army with this big, well armed ship. He knew how to fight and how to live. He hated to part with men. "What happened here?" Stew puffed mightily on his pipe and laid it down. "Nothing much, if they hadn't shot two of my gunners." A tiny sigh escaped Blair's lips. Then Jerry Graham was safe. "Night work," Stew said briefly. "Two ships passed and signalled with our flags for permission to enter. I gave them the okay after checking their numbers and the flight charts. They didn't go into the tunnel. I saw them start heaving stuff out into space at the tunnel mouth. "It was pretty dark, but I recognized the stuff they were tossing out." He paused, then said, "Space mines." "They planned to blow the head of the tunnel?" Stew nodded.