From Jon Fasman's review:
A myth, Pelevin explains, can refer either to an explicative, time-honored story or to "a widely held but false belief or idea." From that telling dual meaning Pelevin draws the twin premises of his book: first, that progress naturally harbors hostility to the lessons and belief systems contained within myths, and that "the concept of progress has been around for so long that now it has all the qualities of a myth. It is a traditional story that pretends to explain all natural and social phenomena. It is also a belief that is widespread and false." The second premise reminds you that Pelevin, for all his literary pyrotechnics, has a background in science (he was trained as an engineer); for him, myths function as the mind's "shell programs: sets of rules that we follow in our world processing, mental matrices we project onto complex events to endow them with meaning." Hence this novel, in which technology and myth conspire to trap and disembody eight people, who end up returning to humanity's primal drives — love, religion, storytelling — in order to make some sense of their surroundings.