One might define the current relationship between the novelist and the biographer as a rather complicated game of dressing-up, in which each player’s aim is to put on most of the clothes that his opposite number has taken off. While a certain kind of novel has grown denser and more self-consciously tethered to the world it affects to describe (and thus gets commended for the diligence of its ‘research’), so ‘life writing’ has turned more eclectic, less constrained by chronological decencies and sometimes regarding even facts as a hindrance to its schemes. There have been ‘hybrid’ biographies, and downright ‘experimental’ ones (see, for example, Andrew Motion’s Wainewright the Poisoner). There have been biographies of places, and snapshot studies that attempt to prove some dramatic truth about their subject by focusing on a particular incident or an isolated stretch of time. The general effect, it might be argued, has been to enhance one form’s attractions at the other’s expense. Which is to say that a good deal of modern biography looks unexpectedly creative, while a good deal of contemporary fiction seems downright staid and too obviously plundered from the textbooks.

It would be overdoing things to call Michael Holroyd the godfather of this change of tack, but he has certainly been one of its great cheerleaders. A Book of Secrets is, self-advertisingly, an exercise in the kind of meditative, time-travelling enquiry pioneered in Mosaic, a book about Holroyd’s