Lucy James and Sherlock Holmes must solve a mysterious locked-room murder at London\'s exclusive Diogenes Club.
Emotions intensify and the dangers become life-threatening as they find themselves drawn into lethal conflict with the most ruthless gang leader in London..
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.
Lucy James and Sherlock Holmes must solve a mysterious locked-room murder at London\'s exclusive Diogenes Club