Presently Kreega sat up. He felt himself gingerly. There seemed to be a rib broken--well, that could be fixed. He was still alive. He'd been choked for a good ten minutes, but a Martian can last fifteen without air. He opened the sleeping bag and got Riordan's keys. Then he limped slowly back to the rocket. A day or two of experimentation taught him how to fly it. He'd go to his kinsmen near Syrtis. Now that they had an Earthly machine, and Earthly weapons to copy-- But there was other business first. He didn't hate Riordan, but Mars is a hard world. He went back and dragged the Earthling into a cave and hid him beyond all possibility of human search parties finding him. For a while he looked into the man's eyes. Horror stared dumbly back at him. He spoke slowly, in halting English: "For those you killed, and for being a stranger on a world that does not want you, and against the day when Mars is free, I leave you." Before departing, he got several oxygen tanks from the boat and hooked them into the man's air supply. That was quite a bit of air for one in suspended animation. Enough to keep him alive for a thousand years. * * * * *