A. E. Van Vogt — The War Against The Rull
Panther 1973 Paperback 156 In battle after battle all across the galaxy, the surging forces of Humanity came up against the outposts of the strange, shape-chaning creatures called the Rull... and the Rull always won. It was not merely that they had better ships and better tactics. They had an advantage mankind could not overcome: they could assume any shape they wished. How could mankind beat this new enemy? And how could mankind afford to lose, when its destruction was at stake? Tanned but otherwise good. Good