From publisher blurb:
YOU are the Doctor's only assistant as you face an entire race of mutant warlike beings in INVASION OF THE ORMAZOIDS.
It is the twenty-fifth century. The Doctor has set your coordinates for the rim worlds - a turbulent, primitive, and strange region. There, at the edge of the universe, you are fated to meet Darval, an evil ruler with a fascinating history and bizarre energy.
But of more immediate danger: Darval's Ormazoids, a race of beings originally created to assist him in space exploration but now bred by Darval to be fearless and unstoppable - and to carry out his commands for domination of the universe.