A Plague of Demons Author:Keith Laumer Since WWI, they have been among us; wherever it was said "Missing in Action", the truth has been different, and much more startling. Through their captured combatants, they have filtered into our race, donning the figures of humans and the masks of the civilized. But in their pure naked essence, they are the lowliest of bea... more »sts -- tailless dogs with human hands and skull-like faces. They live upon the flesh of the brain, impervious to battle, indifferent to pursuit. They can only be threatened by an all-out war fought by power-equipped, invulnerable men -- bionic men created to turn back A PLAGUE OF DEMONS."
From the blurb: "Recruits For An Intergalactic War: The Only Thing You Have To Lose Is Your Mind.