Amongst Our Weapons, by Ben Aaronovitch

Back in the Folly after his undercover adventures, Detective Constable Peter Grant has a new trainee in the Special Assessment Unit. Two mysterious murders lead the team of magical investigators in search of a set of platinum puzzle rings. Peter has to leave his beloved London for Manchester to repair relationships with magical engineers the Sons of Wayland. The Folly needs allies to combat a malign medieval spirit inadvertently released by erstwhile colleague Lesley May, while she was pursuing the rings. Meanwhile his other beloved, river goddess Beverley Brook, is about to give birth to twins, which will change their lives forever. The key to this mystery is to expect the unexpected and the same goes for Peter’s future in the police force. This novel was published in 2022, which means it may be a while to wait for any further adventures of Peter Grant, his family and friends. Hopefully not too long.