"Get in there," Vickers said in a voice that brooked no questions. He swung back to the wall separating them from the Arabian embassy. The adjoining bedroom, he saw, was still empty. * * * * * He drew the atomic knife from its holster beneath his burnoose, pressed the stud. A long blade of coruscating atomic energy shot from the handle. The blade went into the wall as if the tough plastic had been butter. With infinite caution, Vickers cut a four foot window into the next building, lifted out the block. "Don't fumble your part," he said over his shoulder. "We may be in a hurry when we come back this way." Without waiting for a reply, he stepped through, fitted the block back into place. His last glimpse of Tani revealed her crouched in the transparent plastic air taxi, her eyes round and frightened as two new moons. * * * * * Vickers didn't hurry. Hope for success lay in two factors: audacity and his peculiar vision which allowed him to see what his opponents were doing and so keep a number of jumps ahead. The Arabs were a mixture of the old and the new. Scientifically, they were on a par with any of the seven great nations, but they clung with superstitious fanaticism to the old customs, the old way of life. The harem was still inviolate, and Vickers knew there would be a guard outside its door. He located him through several walls that acted like layers of cheesecloth to his eyes, dimming the guard's figure but not obscuring it. He found the women. There were four, and half a dozen servants besides. But they were congregated at the pool and in two of the rooms. He could watch them laughing and chatting or swimming in the limpid water. Dark-eyed houris with slender waists and full hips and breasts. It was like a silent film of the ancients. But infinitely more real. And deadly. There was no one in the hall. Satisfied, Vickers left the bedroom, walked swiftly down the carpeted hall until he reached the door at the end. He could see the harem guard leaning against the wall, a burly bearded figure with a hawk nose and a hawk's fierce eyes. An automatic was belted outside his blue and white striped burnoose. Without hesitation or haste, Vickers ran the atomic knife through the lock, forced open the door. The guard spun around, gaping in surprise. He caught sight of Vickers, reached for the automatic. "By Allah!" he began. Vickers cut off his head. The head hit the floor with a thump, rolled a little, came to rest on its stump, staring at Vickers out of open, startled eyes. It upset Vickers, made him a little sick at his stomach. He swallowed, glanced about quickly. Three men, he discovered, were approaching around a bend in the corridor. He had perhaps a minute or a minute and a half before they came into sight.