Bone Gods is a continuation from the last Black London book, Demon Bound, a noir urban fantasy series about an ex-rocker and junkie who is a powerful crow mage - servant to the bringer of death and an ex cop turned private eye who is a Weir, conduit to the crow mage's powers and servant to the guardian of the black gates. In Demon Bound, Jack was dragged to hell by Belial and with his death, Pete went through a mourning phase and life goes on without Jack which doesn't became any better for her either. She was called to a crime scene by her ex-partner, Ollie, at the British Museum in which a dead body was found with occult mark on his chest. Seeking for the meaning of the mark, she asked for help from the Black where she was accosted by a self-righteous radical group whose leader, Ethan Morningstar, had her missing mother on the leash. Apparently the dead guy stole something and Morningstar wanted it and threatened Pete with her lives and everyone she knew if she refuses. Hated being blackmailed like that, she sought for the help of a white witch, Lawrence lead her to supernatural version of The Librarian who gives vague information and explained to her the ripples in the black that threatened the city and something spooked the black from the death. 
 I could go on since the book is literally filled with plot progression in variety of form but I would end up spoiling the book for you. Despite the page numbers, the book is actually very lengthy and action packed within its multitude chapters. To be honest, I never enjoyed an urban fantasy book like this. I do like Nocturne City but I find the stark similarities with Keri Arthur's Riley Jenson series that I called it quit. Black London are set in a contemporary world and filled with noir overtone and goes fluidly with its detective storylines. Despite that I've been drowning with detective fiction of any form, Kittredge surprised me with her style that is unconventional but never redundant. Like the first book, Bone Gods is narrated by Pete and so with Kittredge's style, reading the book had placed you into the shoes of the character and completely immersing yourself into the character. There are stark differences in Pete's personalities than Jack Winters in Demon Bound in written form that I don't think even YA writer Mari Mancusi can pull it off with her vampire books. The differences between Nocturne City and Iron Codex was the level of noir and maturity she pour within every richly descriptive story of a wretched, rusted world where mass death is nothing but a tea party. With the fifth book in two months time, I shall stop myself with this book instead of continuing with the fourth since I wouldn't like it to wait long for the fifth instalment. 
 Personally, I won't recommend the book to female paranormal romance readers who expect romantic storyline to fill the bulk of the book. I find the major grievance in some reviewers of the series is that they expect it to be a run down the mill story of a damsel in distress wearing leather jacket and a gun and a handsome crow-mage who save the world. To be honest, I love the serious tone of the story and I certainly don't want Miss Kittredge to emulate the countless other PNRs had done. Certainly, I would recommend this to all readers but only those would enjoy darker supernatural storylines with foul-mouthed layered characters and richly detailed backdrop of a city with its darkest horror secrets.