I'm really at a loss on how to explain London Falling by Paul Cornell. It's got quite a bit in common with Neil Gaiman's Neverwhere, only much darker. Well, maybe not darker, just...grittier. And lacking in the humor inherent in Gaiman.
We start with two undercover cops, Sefton and Costain, on the last night of an 4 year long sting trying to nick Rob Toshack, sort of the Godfather of London. The two UCs are supervised by Quill, who's suspicious of Costain, since Costain seems to be breaking the first rule of undercover and doing the drugs he's "selling". And processing information on the case in the background is Ross, who we find out is Toshack's niece.
They do manage to arrest Toshack, not long after Costain (while wearing a recording device), manages to out himself and Sefton as UCs. Sefton, in the meantime thinks Costain has it out for him because Sefton is gay. Sefton, in the meantime, goes out of his way to get Costain in trouble as everyone gets rounded up.
Toshack goes quietly, and confesses to everything while being interrogated by Quill. At which point Toshack explodes into a big bloody mess. For no apparent reason.
This sets up thr thrust of the book, wherein the four principles investigate a soil sample found at one of the residences Toshack spent the night before the arrest visiting, only to be gifted with "The Sight". Which manifests itself in such ways as Quill finding his best buddy is being tormented by his Dad's ghost.
As Operation Toto proceeds (and the 4 coppers try to deal with the new gift), we find the chief suspect in Toshack's death is one Mora Losley, who had a season ticket next to Toshack at the West Ham Irons football team. (Football in the case meaning soccer. Since Europeans and Africans have no idea what real football is. Amurika! Heck yeah!) Mora, they figure out, seems to be in the habit of using the bloody explosion trick on anyone who scores a hat trick on her beloved Irons. Of course, they also find out the way to make people explode in blood is to boil three children alive. (Mora really needed a gingerbread house. Of course, given her familiar, she could just have easily lived in a hut dancing on chicken legs.)
As the story progresses, we get insight into all four of our protagonists and their various relationships, and, thanks to the aforementioned familiar, we also get to know Mora's history. Which makes her much more of a sympathetic character. Well, other than that whole boiling children in a big pot to kill people who score three points against a team playing a sport no one cares about.
In this, the first book of what will probably become a series (I say that, since the extradimensional entity Mora works for remains quite enigmatic through the end), we get several themes in what forms the metaphysics of Cornell's world building. Among other things, none of the wonderful abilities work outside London, and one of the running issues is what actual borders London has. Pretty sure the definition used in this is the outerbelt that forms the sigil for the Black hand of Mu, or whatever that joke was in Good Omens. What's true is less important than what's remembered when it comes to the setting.
Also, there is a very strong thread of isolation wrapped around almost every character in the novel. And interestingly, it's the characters' isolation that eventually binds them together. Even if they do more or less form a standard Dungeons & Dragons adventure group in terms of roles within their cell.
I look forward to whatever followup Cornell eventually releases.