Ruth Rendell has probably pulled more surprises on her readers than any other crime writer. But the one she produces with her latest novel is a little unusual even by her standards. Set in the present, The Vault (Hutchinson, £18.99) deals with the discovery of four corpses in the disused coal hole of a Georgian cottage in St John’s Wood. The main investigator is Rendell’s long-running series hero, Chief Inspector Wexford, now retired and living part-time in Hampstead. Called in, a little implausibly, as a police adviser, he copes with what are in effect two murder cases, with different timescales, victims, motives — and killers. He and his wife Dora also find the time to sort out a potentially lethal phase in the love life of their feckless middle-aged daughter.

But Wexford learns only part of the story. Rendell’s more dedicated readers will know more — for the real surprise is that the murder location, Orcadia Cottage, was also the principal setting of her non-series psychological thriller, A Sight for Sore Eyes, a stark fable about the price of love and lovelessness; this came out in 1998 and has now been reissued in paperback. Here she provided a very different perspective on the sequence of events that brought three of the four corpses to the coal hole.

The Vault is a little too discursive to be Rendell at her very best, and Wexford sometimes seems to be too good to be true. But the novel is sharp, astringent and humane. Even a second-division Wexford novel is something to be cherished.