Brian Aldiss 
Interpreter [EPUB ebook] 

Earthman Gary Towler is a pariah. He must interpret the will of the Nuls who rule his planet, Earth, and he’s running out of time to overthrow their plans…The time: thousands of years hence. The whole of the known universe is dominated by the Nuls, a huge, three-armed race, almost as old as time itself.A charge of Nul corruption on an insignificant planet called Earth sets off a dramatic chain of events.