"Yes, yes, I am," Engel managed to say. With the doctor close behind, he followed Marston apprehensively down a corridor to a thick convex window. Marston slid it back and stepped into what resembled a bowl-shaped cockpit, a confusing maze of dials and instruments under a hemisphere of glass. Motioning Engel to a seat, he turned to the dashboard, and the same spot of light which Engel had seen in the Tracer Room flashed on a screen. He jabbed a button twice and picked up a microphone. "Marston to Captain Schaeffer. We're coming down." "Yes, sir. The alien's turned back," a strained voice replied. "He's now walking south on Baxter. Might be on to us, he's acting jumpy." "You sound jumpy yourself, Schaeffer," Marston snapped. "Tell your men to hold their fire this time! All right, I have him on optibeam." Marston spun a wheel sharply, and they were falling. Engel braced himself as a white glistening tower swung away to their left, and the geometric depths of the city loomed up. He saw the doctor take a gun from a compartment, check it, and stand up wavering. His face was a mask of suppressed hate. "We'll dispatch him quickly," he hissed. Engel squirmed. To prevent a ruthless murder he'd have to not only outwit these men but countless police besides. What was worse, with his headache almost gone, his own uncontrollable waves of fear might expose him. * * * * * "He's running," Marston said with a nod at the screen. As the globe shot down past white towers, a spotlight on the glass roof flashed red, and a shrill siren stung Engel's ears. Ahead of them a big globe fled out of their way, its passengers looking back at them, frightened. Black dots on the street scurried to the towers. "I see him!" Dr. Weeve screeched. Below them a man was running past a gray wall of huddled people. He looked at them, dropped a briefcase, and sprinted into the deserted street. Marston chuckled into the mike. "We have him, Schaeffer. Not putting up much of a fight, is he?" "No, sir." Marston glided the globe a few yards above and slightly behind his quarry. As Engel stared down at the man's flapping coat and thin, blond hair, he clenched his fists. It was C. G. The siren moaned to a stop, and in the sudden silence that filled the globe he could hear weary footsteps and anguished breathing. Heavy-lidded eyes narrowed at Engel. "Recognize him?" Engel's mouth opened, and his throat tightened. He closed his eyes and nodded. "Halt, alien!" Marston's voice boomed over a loudspeaker. C. G. whirled, and they saw a soiled, rumpled suit and a trembling small face. A tear spilled down one cheek. "W-who are you?" he cried out. "What do you want?" Marston put the muzzle of his automatic through a gun port and fired. C. G. screamed and fell. Then in bright dusty sunlight he rolled on one side, groaning, and clutched his arm where a dark stain spread slowly down his sleeve.