Holmes and Watson find themselves caught up in a complex chess board of a problem, involving a clandestine love affair and the disappearance of a priceless sapphire. Professor James Moriarty is back to tease and torment, leading the duo on a chase through the dark and dangerous back streets of London and beyond.

Carole Buggé is a well-known mystery writer. She has written several novels featuring Sherlock Holmes, as well as the Claire Rawlings Mysteries series.