Pell twisted into the black maw of the alley and ran silently and swiftly into its depths. His breath came in whistling agonized gasps. Faintly he heard the footsteps of his assailant—now more clearly as the latter turned into the alley after him. Vaguely Pell could make out his silhouette outlined by the dim light that filtered in from the street. "Ugh!" Pell struck a hard surface at the end of the alley with a grunt that he could not stifle. Trapped! Frantically he felt about to find an openin