This is a wonderfullly mind-bending book that works on so many levels it would definitely reward a second reading. Its premise is pretty strange: in a post-apocalyptic England, turned into an achipelago by global warming, a brutal and backward society is ruled by a religion based on a holy text of "revealed truth," The Book of Dave. Fast-rewind to the present and it soon becomes clear that The Book is the psychotic rantings of a London cabbie of the same name, engraved on stainless steel plates and buried in his estranged wife's garden. The purpose of this insanity is to pass to his son "The Knowledge" of London streets, routes and points of interest that cabbies need to memorize to get their license. Intewoven with this is Dave's worldview, venomously warped by rage at the ex-wife, longing for his "Lost Boy," and the side-effects of a stew of mis-prescribed drugs.