Acetate is taped to dustjacket as a cheap DJ protector - but since it is in good shape, I've left it on.

A fix-up, based on stories/novelettes revised from original appearances in Analog (1968-1971.) Those stories are "Fear Hound" (one of my favorites), "Rescue Squad for Ahmed" and "The Missing Man" - which won the Nebula award in 1972 for best novella. The last 100+ pages (chapters 5 to 9) are original to the 1975 hardcover.