Zarreich

Jim Donne, a recent college graduate, comes to live in a small town after the death of his mother, only to discover that all his memories have been wiped out. Now living with what may or may not be his grandmother, he kills what he thinks is a gang leader invading her home. But he panics, wondering whether he's overreacted to a harmless student prank, and he cuts up and hides the body. Soon he finds himself under a ludicrously botched police investigation.
Slipping into hallucinatory fevers, he tries to disappear into a stifling clerical job at a mortgage company in the ruined city of Zarreich. Yet he's soon drafted into a secret commune of twelve dreamers in an underground university he can only faintly remember.