The fearless girl Sally Lockhart, known to readers from her novels Ruby in the Mist and Shadow in the North, hasn't been this happy in a long time. She lives in an old mansion with her young daughter and servants, her business is booming, and her best friends are travelling the world. And then, like a bolt from the blue, a message from the court comes...

Sally soon needs everything - her courage, her natural intelligence and determination - to stand up to a cruel conspiracy alone. As she conducts her own investigation, she comes dangerously close to the tiger - the cunning and vengeful Tzadik. This detective story takes place in London in 1881 and is intertwined with real events of the time.