Flashback by Dan Simmons

America, 2036

A wasteland in economic ruin. Terrorism and ultra-violence plague a once powerful society, whose people's only escape is to numb themselves on flashback - a euphoric yet crippingly addictive drug that allows its users to revisit happier, past experiences.

Ex-cop and addict Nick Bottom has seen flashback destroy his life. All he has left are the flash-induced memories of his beloved wife, taken from him in a fatal car accident. In despair and at rock bottom, Nick receives a proposition from billionaire magnate Hiroshi Nakamura.

Nakamura wants Nick's services.
In particular, his memories . . .