The Herring Seller's Apprentice - L.C. Tyler

Ethelred Tressider is a writer with problems. His latest novel is going nowhere, a mid-life crisis is looming and he's burdened by the literary agent he probably deserves: Elsie Thirkettle, a diminutive but determined individual who claims to enjoy neither the company of writers nor literature of any sort. And as if things weren't bad enough for Ethelred, his ex-wife, Geraldine, is reported missing when her Fiat is found deserted near Ethelred's Sussex home. When the disappearance becomes a murder investigation, the police quickly decide that Geraldine Tressider has been the victim of a local serial killer.

Soon the nosy, chocolate-champing Elsie has bullied Ethelred into embarking upon his own investigation, but as their enquiries proceed, she begins to suspect htat her client's own alibi is not as solid as he claims.