Rivers Of London is the first book in the Rivers Of London series by best-selling British author, Ben Aaronovitch. Reaching the end of his probationary period, Constable Peter Grant is reluctantly headed for the Case Progression Unit until he accidentally shares with DCI Thomas Nightingale that he’s looking for a ghost.

The ghost of Nicholas Wallpenny had earlier told Peter that he’d witnessed a murder, and Peter wanted to know more, even though he doesn’t believe in ghosts. But now he’s working with Nightingale, investigating a very unusual aspect of that murder. And before long, he becomes the default owner of the victim’s dog, Toby, is living in a rather grand Georgian terrace called the Folly, and is apprenticed to a wizard.

He’s learning magic and enjoys working in the Folly’s lab, applying his C-grade science A-levels to researching how it all works. And he is still doing police work, especially anything with a supernatural element. That’s how he ends up helping to dispatch a pair of vampires, and trying to broker a peace between Mother Thames and Father Thames.

But that initial case, after the murderer went on a killing rampage before dying, is still unsolved, there being a magical element involved, and Peter’s co-probationary constable, DC Lesley May’s research has turned up similar disturbances. Getting more information sees Peter performing a necromantic ritual that almost goes very badly wrong.

Eventually, they are tracking down a supernatural entity, a vengeful, malicious revenant, a vampire ghost who seems to have a thing for the traditional story of Punch and Judy, using real people as the puppets. Peter and Thomas lay a trap. And this one does go badly wrong. Someone is shot, there’s a riot at the Royal Opera House where well-dressed opera attendees get quite aggressive, and a bit of time travel before it’s all sorted out.

With its London setting and the mention of so many streets, localities and landmarks, this would be an especially enjoyable read for those familiar with the city, but that doesn’t exclude non-resident readers getting a vicarious London fix. The concept is clever and Aaronovitch gives the reader some quirky characters, snappy dialogue, an interesting plot and plenty of dark humour in this first instalment: more of this cast will be most welcome. A very entertaining read.