|Sphere SF paperback, 1976. Cover by Chris Foss.|
"In the far distant future, the spaceship Star Cluster is searching for certain inhabited planets lost somewhere in the teeming wilderness of outer space. The inhabitants of these planets know the ship is searching for them, but they refuse to reveal their location. Why don't these people want to be found? What is their secret? Discover the astounding answers as you read this gripping, classic tale interstellar adventure by A.E. van vogt, one of the all-time great names in adventurous science fiction."