The Corpse with the Granite Heart (en Inglés) - Cathy Ace

"It will never end until I end it...so I shall..."

Welsh Canadian criminal psychologist Cait Morgan, and her retired-cop husband Bud Anderson, are in London, England, to meet their friend John Silver's freshly minted fiancée, the daughter of a recently deceased Shakespeare aficionado, and captain of industry. The trip is supposed to be filled with art galleries, good food, and Christmas spirit. However, an untimely death at a posh dinner party threatens to send shock waves through the upper strata of London society.

Cait and Bud's desire to seek out the truth is blocked by a shadowy figure who's been tasked with keeping the incident hush-hush, but - as the body-count rises - the investigation develops a dreadful momentum.

This is the eleventh Cait Morgan Mystery, and it finds our usually unstoppable duo running up against the immoveable machinery of power...with tragic consequences.