Then she slammed the door. The taxi roared, bull throated, and leaped forward, bursting a hole in the false wall. Vickers stared after the diminishing air cab, rubbing his mouth with the back of his hand. "I'll be damned," he said softly; "I'll be damned." Then he turned around. He was just in time to see the first of the Arab guards lunge through the hole in the wall of the embassy. Vickers hurled his other gas grenade. The egg-shaped glass bomb smashed against the floor. Plumes of the pale green paralysis gas shot upward. But Vickers didn't wait to see its effect. He left through the hole torn by the air taxi, reached the pavement, began to walk rapidly toward the corner, the snuff-brown burnoose flapping about his ankles. He had seconds only before the pursuit would develop again. The bomb was a delaying action, no more. * * * * * Up ahead he could see a road block, and pedestrians milling around in the street. A net hung from the level above, halting the air traffic. The ISP was on the job. "Out of the frying pan into the fire," he thought grimly. He glanced back toward the house, although the Arabs couldn't possibly come through the room until they'd procured a fan and blown the fumes clear. An ISP patrol boat was gliding slowly up the street behind him. It was manned by two men and was traveling just above the surface traffic. A shallow, heavily armed and armored craft, it reminded Vickers of a giant ray as it floated lazily through the air. He jumped to the edge of the pavement, waved the patrol boat down frantically. It gave a low moan on its siren, swung in to the curb. The door opened. The two men inside wore uniforms--smart blue breeches and blouses trimmed in gold with the ISP insignia--three interlocking worlds representing Earth, Venus and Mars--emblazoned on their shoulders. They were both young and clean cut. Only their eyes looked old and hard. "What's the trouble?" the officer nearest Vickers asked shortly. "I saw him!" Vickers sounded excited. "I saw him!" "Saw who?" "The mutant!" The ISP agents exchanged glances. At that instant Vickers hit the one on the outside in the temple. He hit him with the handle of the atomic knife. The man slumped forward, bumped his head against the slanting windshield. Vickers was already sliding in beside him. He shoved the unconscious agent to the floor boards, pressed the stud on the knife handle. The blade of sparkling flame glittered into life. "Take us up!" he said to the startled man at the controls; "and don't touch the radio!" Almost as an afterthought he added softly: "I'm Vickers. I'd just as soon die now, all at once, as be sent back to the Jupiter Mines to die by degrees." The ISP man blanched. He lifted the patrol boat into the air, sent it scooting down the street. He kept dropping his eyes to the shimmering blade of flame. "Don't get that thing too close," he pleaded hoarsely.