The Attenbury Emeralds

In 1936, Dorothy L. Sayers abandoned the last Lord Peter Wimsey detective story. Sixty years later, a brown paper parcel containing a copy of the manuscript was discovered in her agent's safe in London, and award-winning novelist Jill Paton Walsh was commissioned to complete it. The result of the pairing of Dorothy L. Sayers with Walsh was the international bestseller Thrones, Dominations.
Now, following A Presumption of Death, set during World War II, comes a new Sayers-inspired mystery featuring Lord Peter Wimsey, revisiting his very first case. . . . It was 1921 when Lord Peter Wimsey first encountered the Attenbury Emeralds. The recovery of the gems in Lord Attenbury's dazzling heirloom collection made headlines—and launched a shell-shocked young aristocrat on his career as a detective.
Thirty years later, a happily married Lord Peter has just shared the secrets of that mystery with his wife, the detective novelist Harriet Vane. Suddenly, the new Lord Attenbury—grandson of Lord Peter's first client—seeks his help to prove who owns the emeralds. As Harriet and Peter contemplate the changes that the war has wrought on English society—and Peter, who always cherished the liberties of a younger son, faces the unwanted prospect of ending up the Duke of Denver after all—Jill Paton Walsh brings us a masterful new chapter in the annals of one of the greatest detectives of all time.