Amongst Our Weapons feels like one of those points in a long running series where the characters have become so familiar that dropping back into their world is like meeting old friends, except these friends have a worrying tendency to encounter gods, ghosts and magical murderers.

Peter Grant is still dealing with the practical consequences of being a police officer who happens to know that magic is real. This time, the investigation begins with a particularly nasty murder and quickly develops into another reminder that the supernatural side of London is never going to leave him alone.

Peter is becoming more confident without ever becoming completely comfortable with what he is dealing with. He has learned enough magic to be dangerous, but remains a copper at heart. The investigation therefore has the practical detail you would expect from a police procedural, but Aaronovitch never needs to drown the reader in it. The police side simply gives Peter’s investigation some weight.

When the supernatural elements start becoming stranger, that grounding makes them feel more convincing because Peter has to deal with them as part of an actual investigation rather than simply wandering around in a fantasy novel.

And there is plenty of fantasy to deal with.

The Rivers of London universe continues to expand in peculiar directions, mixing folklore, gods, magic and the modern world with casual confidence. Peter’s biggest advantage is that he has stopped being surprised by the impossible. His reaction is increasingly, “Right, that’s apparently a thing. What do I do about it?”

Probably the correct attitude when your job involves magical rivers and supernatural politics.

Peter’s personal life is also moving into a rather important new phase. His relationship with Beverley is now heading towards parenthood, and that impending change gives his increasingly chaotic existence another dimension. Becoming a father is going to be complicated enough without the supernatural world and all the other baggage that comes with being Peter Grant.

There is also Peter having his own trainee in the art. Seeing him on the other side of the learning relationship is entertaining, particularly because Peter is hardly a conventional example. He has learned from Nightingale, made plenty of mistakes along the way, and now has to pass some of that knowledge on.

The humour remains one of the series’ strengths. Peter’s dry observations continue to puncture moments that might otherwise become overly dramatic, while the sheer absurdity of some situations provides plenty of laughs. Even the title and chapter headings should amuse anyone who grew up with Monty Python. They are exactly the sort of ridiculous touches that make these books fun.

And then there is Kobna Holdbrook-Smith.

His narration is once again excellent. By this point, his Peter Grant is so well established that hearing him speak makes the character immediately present. Holdbrook-Smith handles the conversational rhythm beautifully, but his real strength is the way he differentiates the enormous cast without making the performances feel exaggerated.

He is particularly good at Peter’s understated humour, but handles the darker material with enough restraint that serious moments are never overwhelmed by the comedy. His performance continues to make the audiobook feel like a fully inhabited world rather than someone simply reading the text aloud.

If I have any complaint, it is that the ever expanding mythology occasionally leaves me wanting more answers. But honestly, that is a fairly minor criticism. Part of the fun is discovering another strange corner of the world and wondering where Aaronovitch might take it next.

Amongst Our Weapons is a thoroughly enjoyable chapter in Peter Grant’s increasingly complicated life. It has murder, magic, police work, gods, family complications and enough dry humour to keep everything moving.

The procedural realism gives the supernatural story its foundations, while Peter’s increasingly comfortable relationship with the impossible lets the series continue to grow without losing its identity.

Add Kobna Holdbrook-Smith’s superb narration, a cast of characters I enjoy spending time with, and the prospect of Peter becoming a father, and there is very little to complain about.

Peter Grant has survived magic, murder and supernatural politics.

Now he has a trainee and a baby on the way.

What could possibly go wrong?

Buy your copy here