The synopsis from amazon.co.uk:
Searching for truffles in a wood, a man and his dog unearth something less savoury - a human hand. The body, as Chief Inspector Wexford is informed later, has lain buried for ten years or so, wrapped in a purple cotton shroud. The post mortem can not reveal the precise cause of death. The only clue is a crack in one of the dead man's ribs. Although it covers a relatively short period of time, the computer stores a long list of Missing Persons. Men, women and children disappear at an alarming rate, nationwide something like 500 every day. So Wexford knows he is going to have a job on his hands to identify the corpse. And then, only about twenty yards away from the woodland burial site, in the cellar of a disused cottage, another body is discovered. The detection skills of Wexford, Burden and the other investigating officers of the Kingsmarkham Police Force are tested to the utmost to discover whether the murders are connected and to track down whoever is responsible.