Having escaped being sacrificed to a cult, Isabelle Barnes wants justice, and with the help of Tommy Muldoon, maybe the one honest cop left in Arkham, she starts pulling at a string of disappearances stretching back years. A noir prequel completing the origin story begun in the novella Hour of the Huntress, it follows Isabelle into Arkham's rot ahead of her career as an investigator.
Summary by Loreful, from public sources