"Come on." Reinhart moved away, crouching and running. He glanced at his watch. _Almost time._ A few more minutes. A group of lab guards appeared ahead of them. Reinhart fired. Behind him his police fired past him, violet shafts of energy catching the group of guards as they entered the corridor. The guards spilled apart, falling and twisting. Part of them settled into dust, drifting down the corridor. Reinhart made his way toward the lab, crouching and leaping, pushing past heaps of debris and remains, followed by his men. "Come on! Don't stop!" * * * * * Suddenly from around them the booming, enlarged voice of Sherikov thundered, magnified by rows of wall speakers along the corridor. Reinhart halted, glancing around. "Reinhart! You haven't got a chance. You'll never get back to the surface. Throw down your guns and give up. You're surrounded on all sides. You're a mile, under the surface." Reinhart threw himself into motion, pushing into billowing clouds of particles drifting along the corridor. "Are you sure, Sherikov?" he grunted. Sherikov laughed, his harsh, metallic peals rolling in waves against Reinhart's eardrums. "I don't want to have to kill you, Commissioner. You're vital to the war: I'm sorry you found out about the variable man. I admit we overlooked the Centauran espionage as a factor in this. But now that you know about him--" Suddenly Sherikov's voice broke off. A deep rumble had shaken the floor, a lapping vibration that shuddered through the corridor. Reinhart sagged with relief. He peered through the clouds of debris, making out the figures on his watch. Right on time. Not a second late. The first of the hydrogen missiles, launched from the Council buildings on the other side of the world, were beginning to arrive. The attack had begun. At exactly six o'clock Joseph Dixon, standing on the surface four miles from the entrance tunnel, gave the sign to the waiting units. The first job was to break down Sherikov's defense screens. The missiles had to penetrate without interference. At Dixon's signal a fleet of thirty Security ships dived from a height of ten miles, swooping above the mountains, directly over the underground laboratories. Within five minutes the defense screens had been smashed, and all the tower projectors leveled flat. Now the mountains were virtually unprotected. "So far so good," Dixon murmured, as he watched from his secure position. The fleet of Security ships roared back, their work done. Across the face of the desert the police surface cars were crawling rapidly toward the entrance tunnel, snaking from side to side. Meanwhile, Sherikov's counter-attack had begun to go into operation.