H. Beam Piper 
Graveyard of Dreams [EPUB ebook] 

Conn, the son of a melon planter on the planet Poictesme, returns home after five years on Earth, studying. And spying. The planet had been used as a military staging point during the last interstellar war between the Federation and the System States Alliance, and somewhere among the leftover war debris on the planet is rumored to be the supercomputer that won the war. Many believe that this supercomputer can provide the answers to lift Poictesme out of economic stagnation and make it a prosperous place again. Conn has been gathering information just for this purpose – the search is on…