The light that never was

Humanity has stretched out over thousands and thousands of worlds. Each planet is virtually independent from one another. Various intelligent species have been discovered but humans start putting them in camps, killing them, refusing to grant them any rights, and branding them with derogatory names (for example, animaloids). This massive anti-animaloid furor spreading across the populated worlds threatens to envelope the tourist-trap planet Donev. However, Donev does not appear to have any indigenous animaloids of their own.