Ubik

Glen Runciter runs a lucrative business, deploying his teams of anti-psychics to corporate clients who want privacy and security from psychic spies. But when he and his top team are ambushed by a rival, he is gravely injured and placed in half-life, a dream-like state of suspended animation. Soon, though, the surviving members of the team begin experiencing some strange phenomena, like Runciter's face appearing on coins and the world seeming to move backward in time. As consumables deteriorate and technology gets ever more primitive, the group must do something to stop the time shifts before they all disappear. But first they need to find out what is causing the shifts and what a mysterious product called Ubik has to do with it all.
Ubik deals with the most classic of Philip K. Dick themes: the perception of reality. In a world with psychics, anti-psychics, and the virtual reality of half-life, it is almost impossible to tell just what is real and what is a dream, right to the last word. Named one of Time's 100 greatest novels, Ubik is both a meditation on reality and a mind-bending puzzle.
Annotation
Glen Runciter is dead--or is everybody else? Somebody died in an explosion orchestrated by Runciter's business competitors, but it's hard to tell who. Filled with paranoic menace and unfettered slapstick, Ubik is a metaphysical comedy of death and salvation--which comes in a convenient aerosal spray, to be used only as directed.