Inara Caan is an embittered vestal to The Order of the Avenging Hand. Her job, traveling worldwide with her demon partner, using magic to destroy monsters and mythological creatures wherever the Order finds them. Her next hunt takes her to Boston. She expects to find villainy beyond compare. Instead, she has been tasked with killing a happy family with a young daughter.

For reasons she doesn't understand, the Order betrays Inara and sends a winged assassin to kill her. She goes on the run, taking the family with her. She battles her way through the streets of Boston, finding help in the unlikeliest of places. As enemies close in from all sides, she stretches the limits of her power trying to save everyone. She may escape the Order but not the demon bound to her soul.