P. D. James 
Taste For Death 

Two men lie dead in the vestry of a London church, their throats cut with brutal precision. One is Sir Paul Berowne, rich, cultivated and elegant; the other is an alcoholic vagrant. Challenged with the investigation of a crime that appears to have endless motives, Adam Dalgliesh explores the sinister web spun around a half-burnt diary and a violet-eyed widow who is pregnant and full of malice—all the while hoping to fill the gap of logic that joined these two disparate men in death…From the Trade Paperback edition.