ConSentiency Universe Series by Frank Herbert

"The Tactful Saboteur" is a novelette by the science fiction author Frank Herbert which first appeared in Galaxy Science Fiction magazine in October 1964. It is notable for establishing the setting for Herbert's ConSentiency universe.

Suddenly - the end of all life throughout the entire Galaxy! It was only weeks away, or days - or even hours. It all depended on the survival of the last of the entities known as Calebians.But the Caleban was dying - subjected to systematic torture by the richest, most wicked woman in the Galaxy. Unless she could be stopped, the end was only a few days away, or hours - or even minutes!

Beyond the God WallGenerations of a tormented human-alien people, caged on a toxic planet, conditioned by constant hunger and war-this is the Dosadi Experiment, and it has succeeded too well. For the Dosadi have bred for Vengeance as well as cunning, and they have learned how to pass through the shimmering God Wall to exact their dreadful revenge on the Universe that created them . . .