The Blue Diamond (The Daughter of Sherlock Holmes Mysteries, 6)

Written by Leonard Goldberg
Review by Valerie Adolph

In London in November 1917, Dr. Watson, with his son and daughter-in-law, continues the detective work of Sherlock Holmes. Watson is older now and suffers from cardiac issues; his medication plays a part in this novel. The younger Watson, also a doctor, has married Joanna, daughter of Sherlock Holmes. Joanna is much like her late father, picking up even the faintest clues instantly and plotting complex strategies to foil evil-doers.

Joanna and the Watsons are asked by the commissioner of Scotland Yard to enquire into the theft of a large blue diamond, stolen from the governor general of South Africa as he slept in a London hotel room. This diamond, to be presented to the king, was of immense value; in the wrong hands, the gem could be sold to help the Germans purchase armaments for use against the Allies. Joanna is immediately full of questions, and the three detectives are hot on the trail of the diamond with the intention of identifying the thief and preventing the stone from falling into German hands.

The author has remained close to the style and themes of the Sherlock Homes mysteries. The writing style is slightly archaic and the plot complex and full of unexpected twists, as one would expect. That said, Sherlock’s daughter Joanna—the brains of the trio, who pulls the two eager but baffled Watsons along—is surprisingly featureless. As her father’s daughter, she is intelligent, sharp-witted and thorough, but otherwise she comes across as just another man on the team.

This novel of investigation follows an interestingly convoluted path. A reader who has enjoyed the Sherlock Holmes mysteries might also enjoy this one.