Performed by acclaimed audiobook narrators Simon Prebble and Wendy Tremont King.

Lucy James and Sherlock Holmes must solve a mysterious locked-room murder at London's exclusive Diogenes Club. But Lucy is still coping with the traumatic after-effects of their last case, and her romantic relationship with a handsome young police detective is growing more complex.

Emotions intensify and the dangers become life-threatening as they find themselves drawn into lethal conflict with the most ruthless gang leader in London.