Carlson straightened. He weighed Ro's words before answering. Finally he said, "I didn't want to make trouble. It was a bad time, and senseless, besides. Charlotte and I are planning to be married when we return to America. It's not as though Grimm was still in the running. I'm sure he'll see reason when we tell him. It's foolish to be enemies." "Why don't you take her for your wife here on Mars? That would end the trouble completely." Carlson seemed surprised. "It wouldn't be legal. Who would perform the ceremony?" Ro seemed puzzled, then he laughed. "Last night I thought that we on Mars are backward. Now I'm not so sure. When we find our mates here, we take her. There is no one to speak of 'legal' or 'ceremony.' After all, it's a personal matter. Who can tell us whether it is 'legal' or not? What better ceremony than a kiss and a promise?" He bent back to his work chuckling. "I could argue the point," Carlson laughed. "I could tell you about a place called Hollywood. Marriage and divorce is bad enough there. Under your system, it would really be a mess. But I won't say anything. Here on Mars your kiss and a promise is probably as binding as any ceremony." Ro didn't speak. He didn't concentrate and transmit his thoughts, but kept them to himself. The pictures he'd received from Carlson were confusing. The business at hand was more grim and important than untangling the puzzle. * * * * * They finished their work and seated themselves close to the edge of the cliff. Carlson was impatient. The inactivity rasped on his nerves. Ro stared anxiously at the spot where Na would make her appearance. The waiting was hard for him, too. Pictures of the girl stumbling and being caught in her chase with the rat men flashed through his mind. He flinched at what would happen then. It would cost, not only his own life, but the lives of those who had gone to the sphere. Suddenly his fears were wiped away. Na appeared at the point he watched. She burst from the woods, running swiftly. A few seconds later, five rat men came into sight. One of them carried a ray gun. The running figures looked tiny from the height of the cliff. They would make very poor targets. But a glance at the narrow point below reassured Ro. Even if the stones went wild, they would still land in that small area. There was no chance of their missing. Na had entered the narrow strip. She seemed to be tiring. The rat men gained. Ro bit his lower lip and clutched the stones in his hands more tightly. Carlson crouched behind the larger rocks and boulders, ready to roll them over the ledge. The rat men entered the pass. Na had already passed below and was almost to the end, when she stumbled. Her head struck the hard ground as she pitched forward and she lay still. Ro's heart leaped in his breast. "Now!" he shouted, and let fly with one of his stones.