[Transcriber Note: This etext was produced from IF Worlds of Science Fiction January 1953. Extensive research did not uncover any evidence that the U.S. copyright on this publication was renewed.]...

The third night of the Marco Four's landfall on the moonless Altarian planet was a repetition of the two before it, a nine-hour intermission of drowsy, pastoral peace. Navigator Arthur Farrell—it was his turn to stand watch—was sitting at an open-side port with a magnoscanner ready; but in spite of his vigilance he had not exposed a film when the inevitable pre-dawn rainbow began to shimmer over the eastern ocean. Sunrise brought him alert with a jerk, frowning at sight of two pinkish, bipedal A