The first death looked like a suicide. But someone had tucked a picture of an angel and a handful of white feathers into the banker's pocket before pushing him in front of a train. A killer is stalking The Square Mile—the financial district in London—an avenging angel intent on punishment. But why these victims? What were their sins?

Psychologist Alice Quentin swore she'd never get involved with police work again. Her duty is to the living, not the dead. But she owes Detective Don Burns a favor. He was the one who would sit for hours when the last case they worked on together had landed her in the hospital. That case had clearly taken its toll on him, and his career, too. So when he comes begging for help, how can she refuse?

In order to find the murderer, Alice and Detective Burns must dig deep into the toxic heart of one of the major financial centers in the world. A place where money means more than life, and no one can be counted innocent.