- Completely Different Title:
- Czech: Foxglove Summer becomes Záludné Léto ("Sneaky Summer"), in a partial example.
- The series as a whole was retitled Le Dernier Apprenti Sorcier ("The Last Sorcerer's Apprentice"). Long story short, this is now a major Artifact Title.
- Moon Over Soho becomes Magie Noire à Soho ("Black Magic in Soho").
- Foxglove Summer's French title, Les Disparues de Rushpool, translates as "The Missing of Rushpool".
- Whispers Under Ground becomes Ein Wispern unter Baker Street ("A Whisper under Baker Street").
- Broken Homes becomes Der Böse Ort ("The Evil Place").
- The Hanging Tree, in a more minor example, is Der Galgen von Tyburn ("The Gallows of Tyburn").
- Japanese: Whispers Under Ground became "The Wizard of the Subterranean Labyrinth".
- Market-Based Title: Book one was retitled as "Midnight Riot" for the US release, ostensibly because American readers need something more dynamic to catch their interest.
- Schedule Slip:
- The ever changing release date of the third and fourth novels, the former which slipped from June to October and the latter which slipped from a June release to November.
- The Hanging Tree's release date slipped all the way from June 2015 to September 2017, but then (thankfully) was rescheduled for release in November 2016.
- Unintentional Period Piece: A strangely recent example, but on his blog, Aaronovitch frequently laments that the Met reinvents itself so often the books are instantly dated. Usually this just means he has to change exactly what the Folly's official designation is, but in Broken Homes he came up with the phrase "Working together for a stranger London" as a play on the Met slogan "Working together for a safer London", and they immediately stopped using it.
- What Could Have Been:
- Word of God states that the book series was originally meant to be a TV series described as Prime Suspect meets Ars Magica. Paul McGann would have played Nightingale and Peter would have been a woman named Simone. There would have also been an entire team of wizards working for the Met.
- Foxglove Summer, where Peter goes on an investigation to the countryside, was originally going to be the second book, but the publishers insisted that there should be more books establishing Peter as a City Mouse before he was taken out of his comfort zone.
Trivia / Rivers of London