"This man is a spy for Earth," a voice droned, as the telecaster vibrated and a photo of Harry Horn flashed on the screen. "Ten thousand credits for this man, dead or alive. Contact Lazar of the Security Police. Harry Horn. Thirty-four, five feet, eleven inches, one hundred and seventy-two pounds." Lynn Brickel snapped off the humming machine. She frowned. Horn had been high in the Martian Security Police, one of Lazar's top men. Now Horn turned out to be a spy for Earth. Why hadn't she been tol