Maureen Duffy has always been an arresting, versatile, difficult writer, intersecting most of her novels with either oblique or overt social commentaries. Here she is at her most austere, not only in her conjectural hypothesis, as advanced by Meepers, a half mad squatter in a porter's uniform fossicking through London, the city of bones, but also in the single words which defeat the eye (archaeopteryx, krumhorns) or the richly narcotic prose to which she's addicted. On the one hand there's the ""psychic masturbator, Meepers, who claims, in a paper, that London became uninhabited at the end of the Roman occupation during that blurred two-century hiatus; still he also contends that civilization is ""irrepressible."" On the other hand there's the professor Ponders, to whom he submits his theory, who is both disconcerted and dogged by him during a bleak summer in his life while Ponders views the overcrowded, polluted city around him with equal dismay. In between there are vistas from the more primal past of seal people and barbarians and Normans--boars and wolves and forest as thick as ""pubic hair."" One of the difficulties of Miss Duffy's novel is that human contacts (could they not have been drawn more decisively between her professor and his ""Meepers-creepers""?) are almost nonexistent and hardly relate to the reader. What is to warm this ""doombrief"" of all the litter around the Albert Memorial or the significant debris under it, part documentation, part photomontage? The faith of a cranky messiah or the fire on the next street corner?