- Blooper: This book has been produced twice as an audiobook, once narrated by Richard Davidson and once by Michael Beck. There are oddities:
- Davidson pronounces Judge Houghton's name differently depending upon whether it is part of the nickname "Shootin' Houghton" (WHO-ten) or not (HOW-ten), which makes for a very strange experience when the two names are being used interchangeably. Michael Beck consistently pronounces it WHO-ten.
- In both versions, Teresa Corazon's name is given as "Claudia Corazon." Connelly's website manager, when asked about this, suggested that the audiobooks may have been recorded from earlier drafts of the book.
- In the text version of the book, Buddy describes the TV show he is watching when McCaleb arrives at The Following Sea as "a show about this task force ..." but the Davidson-narrated audiobook calls it "some shit on TV, a show about ...." The show, as noted on the Tropes page, was almost certainly Level 9, and depending on when that line was edited, it's possible that Connelly was expressing his feelings about the TV show itself, it's short run, or his own involvement with it, or possibly just joking around a bit. May also be explained by the "earlier draft" theory. This troper has not confirmed whether this exists in the Michael Beck version.
- Creator Thumbprint: A downplayed one: Connelly has for years used "hike" to describe someone shrugging their shoulders. In this book people "shake" their shoulders, albeit "shrug" is used several times as well. Only Wiggan, while testifying, "hikes" his shoulders.
- Apparently averted, later revealed to have been played straight: In the prologue, Gunn, not yet identified to the reader, tells Bosch "Fuck you." Later, we find out he was killed shortly thereafter.
- Foreshadowing: The term "lost light" is used and explained as being a phenomenon observed by tunnel rats (like Bosch) where even in a completely dark environment, some light appears to be visible. It foreshadows that Bosch does manage to overcome the demons very much on display in this story. It's also the title of a later Bosch novel.
- Fridge Brilliance: Connelly used a Switching P.O.V. in his last novel, too, and like that story, this one leaves it open (somewhat) to the reader to wonder whether Bosch (like Cassie) really did kill Gunn (like the mark in the hotel), until it's made clear that he didn't (she didn't, either). The Fridge part comes into play when you realize that the other P.O.V. in Void Moon was a legitimate bad guy who did very bad things, which sort of slants the reader's expectations toward believing that Bosch might have crossed over.
- Genius Bonus: A lot of very overt characterization of Harry Bosch is done by way of discussing his medieval artistic namesake. But balancing that is a lot of comparatively subtle characterization of Terry McCaleb that is done with allusion and imagery taken from a different medieval personage: King Arthur. McCaleb is The Hero and Lawful Good, almost to the point of being The Cape to Bosch's The Cowl; after serving his country, he retired with a serious medical condition and moved to Avalon (literally) where he does fishing charters; now, he returns to solve one last case.
- Harsher in Hindsight: The #MeToo movement made clear that the sort of intimidation testified about by Annabelle Crowe was absolutely a real thing that actresses go through.
- Hilarious in Hindsight: For the second book in a row, some bad guys drive a Lincoln. A little bit of Early-Bird Cameo for a car soon to be indelibly connected to Mickey Haller.
- Running Gag: Well, two instances don't really make a "running" gag, but nevertheless, this is the second book in a row that features Porky Pig's famous Catchphrase at the climax.
- Shown Their Work: As with Blood Work, a lot of details about the ramifications of a heart transplant get discussed.
Trivia / A Darkness More Than Night