The progress they made was slow, but gradually the distance between them and Oan camp grew. Ro increased his pace when silence was no longer necessary. The four white people stumbled ahead more quickly. "We journey out of the valley and around the face of the cliffs," Ro told them. "After a short while, we will meet Na." "Who is Na?" asked the girl. "She is the one I have chosen for my mate," Ro answered. The white girl was silent. They traveled quite a distance without communicating. Each was busy with his own thoughts. Finally the man with the silver hair asked, "Why did you risk your life to rescue us?" "With your help I will avenge the death of my father and brothers and the men of my tribe." He stopped walking and stared around him for a landmark. They had traveled far along the foot of the cliff. According to the plan Na should have met them minutes ago. Then he gave a glad cry. Squinting ahead he saw an approaching figure. It was--His cry took on a note of alarm. The figure was bent low under the weight of a burden. It was a rat man, and slung across his shoulders was a girl. Ro's body tensed and quivered. A low growl issued from deep in his throat. He charged forward. The Oan saw him coming and straightened, allowing the girl to fall. He set his twisted legs and bared his fangs. The fur on his back stood out straight as he prepared to meet the young Martian's attack. Ro struck his foe head on. They went down in a frenzied bundle of fury. The rat man's tail lashed out to twist around Ro's neck. With frantic strength, Ro tore it away before it could tighten. Ignoring the Oan's slashing teeth, the young Martian pounded heavy fists into his soft stomach. Suddenly shifting his attack, Ro wrapped his legs around the rat man's waist. His hands caught a furry throat and tightened. Over and over they rolled. The Oan clawed urgently at the Martian's choking fingers. His chest made strange noises as it pleaded for the air that would give it life. But Ro's hands were bands of steel, tightening, ever tightening their deadly grip. Then, as suddenly as it had started, it was over. The rat man quivered and lay still. Ro dismounted the limp body. His face wore a wildly triumphant expression. It changed as he remembered the girl. He ran to her side. Na was just opening her eyes. She stared around her fearfully, then smiled as she recognized Ro. The young Martian breathed a sigh of relief. Na turned her head and saw the body of the rat man. She shuddered. "I was coming down the side of the mountain," she said. "I saw him standing at the foot. The shadows were deceiving. I thought it was you. It wasn't until too late that I discovered my mistake." Ro gathered the girl in his arms. He spoke softly to her to help her forget. * * * * * When she had recovered from her shock, the small group traveled on. Ro led them about a mile further along the base of the cliff, then up, to a cleverly concealed cave.