Paul Magrs' imagination seems uncomfortably confined within the constraints of Doctor Who. He displays intimate knowledge of the show but, still within the fiction, points out what he perceives as its shortcomings as if to prove he's above that sort of thing really, simultaneously pre-empting any critical objections to such unconstructive post-modernity with didactic dispatch. Thus Verdigris, despite an abundance of inventive, catchy ideas - some invaders appear to have previously inhabited other fictions, and members of UNIT are rendered more literally two-dimensional - is characteristically rendered impenetrable to all but the devoted. Manifestations of the author's joy in forcing unlikely collisions of character, situation and transportation were plentiful in his earlier novels featuring the tiresome Iris Wildthyme, who reappears yet again here, visiting the third Doctor's home in 1973. Further such bizarre juxtapositions appear in Verdigris, which would be fine given adequate justification or explanation. That many intriguing ideas are inconclusively resolved leaves the discomfiting impression that they are no more than gimmicks.

Even the wearisome in-jokes lack focus. It's not clear whether it is the recent 8th Doctor story arc or some aspect of the TV show to which the author, through his pet character Iris, ascribes the term "canon-death". A metaphor within an internal narration, in which Iris claims to be "one of many forces... looping around the Doctor's past... giving him extra interesting times", indicates a misguided belief that such annoying, knowing asides qualify as astute satirical comment. Certainly other authors pioneered this, but most have grown out of it by now, and surely someone with Magrs' ability and reputation should rise above it.

Iris tells her young companion Tom - and there's an unsubtly evocative name for you - that she's not sure she needs an active deconstructionist. Readers will be accompanied by one for the duration of Verdigris; Paul Magrs destructively subverts 1973 Doctor Who - and a few other programmes, in passing - while remaining too much in thrall to it to be truly iconoclastic. Or if such is his intent, it's difficult to discern, and that has to be an indictment in itself.