For a young subway cop, a jumper is always a traumatic thing. This time however it is the fact that the jumper survived, that will make things so much worse. For his survival leads Lucy Hanlon to review the CCTV footage and see, clear as day, that this jumper didn't jump at all. He was pushed. Pushed by someone or something, that wasn't there.

That push and the evidence of it, pushes Lucy herself toward similar cases, to the unofficial files kept by Detective Madden and to his evidence of The Exchange Hex: A strange web of incidents, scraps of evidence and works of dark magic that connect numerous murders to one woman and her unending thirst for vengeance.

Vengeance that, as Lucy is about to find out, will be taken with no regard for who else might be harmed. Hell hath no fury, like a woman scorned.