"The Rithian Terror" is a novel by Damon Knight, originally published as a short story named "Double Meaning" in 1953, and published as half of an Ace Double in 1965. The other half of the Ace Double was a collection of four short stories, also by Damon Knight.
When I started reading this book, I thought I was finally getting to come across some of the backwards opinions of the early days of the 1960s. Our hero, a square jawed security officer of the galactic empire, is trying to capture a strange squidlike alien who has infiltrated earth, hiding inside a human body. Our hero, Thorne Spangler, has an advisor from a distant world who has had contact with the aliens. The advisor, Mr. Pembun, is from a planet with a creole culture. Spangler thinks of them like this:
Low browed, dull-eyed loafers, breeders, drinkers and brawlers, speaking an unbelievable tongue corrupted from already degraded English, French and Spanish.
If that sounds like a bad start to the book, it quickly becomes apparent that Damon Knight and Thorne Spangler have very different views on the world, and that this book was written with a
villain protagonist. Spangler is an imperialist and racist who acts like a petty tyrant, is rude with subordinates, and who is physically abusive to his
fiance. While the hunt for the infiltrating alien squid provides impetus for the action, the story is really a psychological drama where Spangler's faith in the
reactionary society is shaken by needing to use the help of a "colonial" to try to catch the elusive alien. And of course, the suspicious Spangler also wonders if "The Colonial" Mr. Pembun is working with the alien.
This is also one of the more densely plotted Ace Doubles I have read. While I have appreciated all of the Ace Doubles I have read, some of them have required me to get in a certain reading groove. This book I picked up and wanted to keep reading. Presenting an action story that doubles as a psychological portrait is not easy to do, but Damon Knight pulls it off---up until the last chapter or so of the story, where the conclusion comes too quickly, and the psychological drama is finished too patly. As with many such cases, I put that down to the problems of the format, and the aggressive editing of Ace Doubles.