As for its author, she is no mere writer she has turned 'detective'.

Subtitled An English Mystery, its cover boasts that it was written with 'unique' access to Christie's diary, letters and family, and inside the dust jacket we're promised not a biography but a 'full-scale investigation'. The people at Headline have certainly gone all out to sell it. But perhaps her publisher is worried others may not agree. Thompson clearly feels that she brings a fresh eye - and a special passion - to the already thoroughly picked-over life of the world's bestselling crime writer. Emboldened by this success, Thompson has now tried the same trick again, with Agatha Christie, who was last the subject of a biography (by Janet Morgan) in 1984. Laura Thompson's previous subject was Nancy Mitford, whose biography had already been ably written by Selina Hastings, and she made a decent go of it - even if it wasn't exactly crammed with revelations, and even if her style was, at times, on the toothache-inducing side of syrupy (Nancy herself would have honked like a drain at its worst excesses). So what is the restless biographer to do? Go back, that's what: try someone who was last 'done' a couple of decades ago.

Meanwhile, all the meatiest names have already been done. A few writers die every year, which is helpful, but not all of them, alas, are worthy of their own book. If you read lots of literary biographies, as I do, you can't help but feel that the available pool of subjects is distinctly puddle-sized.

Agatha christie a mysterious life