The Dark Light Years

The Utods appear to be massive, animal-like creatures, wallowing in their own filth. And yet they possess physical and mental powers unknown to man and their world is one of complex philosophy and amazing technology. When interstellar explorers capture a number of Utods, it seems strange that they cannot communicate with them - whilst, somehow, their own ideas communicated themselves to the Utods all too easily. Now Earth is devastated by a terrible conflict of its own making.