His heart pounding, the man scribbles the words in his notebook as fast as he can: "Woman dead in Highgate. Man in caped coat. Milky way and red streaks. I'm being followed."

Hours later, the man's cold body lies in the city mortuary, alongside the woman he couldn't save. And his sister, unconventional nurse Gemma Tate, tracks down troubled police inspector Sebastian Bell to unravel the truth.

Sebastian has enough pressure to solve the murder of an aristocratic heiress without Gemma meddling in his case. But the cryptic sentences she brings him from her brother's notebook could be a crucial lead. If only they knew what "milky way" meant. But as the trail of clues takes them away from the gilded drawing rooms of the nobility and into the dangerous slums of London, how far will their partnership be tested on the quest for justice, and will they both emerge unscathed?

Fans of Andrea Penrose, Deanna Raybourn and Miss Scarlet and the Duke will be hooked on this intricate, compelling mystery set in Victorian London.