Cara Lenoir knows all about secrets. Her existence is one. To keep her sister, the queen, safe from their monstrous father, Cara hides as Carl Fletcher, physician's apprentice. It's either that or die.But when Nathan Cutter shows up to be her mentor, danger lurks closer. What hope does a physician have against a ruthless killer?A deadly plague reaps in the slums. A network of spies is closing in on her. Under the Mantle, Cara has nowhere left to hide.