The man passed some remark to Tumek. But the oldster only shook his head and stood the straighter, face calm, serene ... almost spiritual. Craig corrected his aim a fraction. The firing squad's commander pivoted ... sucked in air to give the final order. Craig squeezed the fire-gun's trigger. A green shaft of flame lanced out. It struck the squad chief square in the chest. He slammed backward--face contorted in a death's-head grimace; already toppling. The squad seemed to freeze in its tracks. Then, as the spell broke, one man started to whirl, whipping round his own weapon. Craig dropped him where he stood. Chaos descended on the guardsmen. Frantically, they lunged for cover. * * * * * Crouched, shadow-silent, Craig slipped from the shop and moved through the murk towards the spot where the prisoner had stood, trusting to confusion and the dark to shield him. "Tumek...." Someone roared, "Look out! It's the Earthman!" The night turned dazzling green with fire-blasts. Craig dived through the shop's shattered window, skidding across the floor on one shoulder. A hand clutched his arm. A cracked voice choked, "Craig Nesom--!" Craig twisted. Tumek's wrinkled face loomed, a dim blur in the gloom. "Quick! This way--" The old man wormed towards the rear of the building. Craig followed. Only then a dark figure was rising and shouting. A fire-gun blazed, close at hand. Craig shot back. The looming antagonist fell away. Old Tumek fell with him. Stumbling to his feet, Craig heaved up the oldster's limp body. With a strength born of sheer desperation, heedless of shouts and fire-blasts, he lunged on, out the rear door of the building. A guard rose in their path. Craig shot him down and charged blindly on, deep into the black alley shadows. A thin whisper from Tumek: "Right ... next crosspath.... Door ... unlocked...." Craig veered. In seconds he was pushing past a heavy gate ... easing it shut behind him once more. The sounds of the guards' rage faded. Gently, Craig lowered Tumek to the ground. An acrid scent rose in his nostrils ... the scent of charred flesh. With a shock, he became aware of the old Baemae's hoarse, labored breathing. Numbly, he ran cautious fingers over the other's withered body. The flesh along Tumek's right rib-casing _crackled_! Then, slowly, the old eyes opened. The cracked voice spoke, the faintest of whispers: "You ... are the Earthman--the Federation agent?" Mute sick, Craig nodded. "Good." The eyes closed again, as if suddenly too heavy. But only for a moment: "Earthman...." "Yes." "Ourobos ... from Xumar--they are Zenaor's weapon." "Ourobos--?" Craig strained close. "Tumek, what are they?" "A ... lifeform. Zenaor's daughter can tell you." The voice of the old Baemae grew weaker. "Zenaor's daughter--!" "Yes. Narla...." "But--" "Only ... one weapon ... against ourobos--crystal." "Crystal--?"