The core of this story is very good. While it doesn't introduce a new group of supernaturals, it does introduce a hidden community of them, namely the kumpania for clairovoyants. In many ways, this community is rather cult-like but it also claims to have solved the problem of insanity that plagues most clairovoyants living on their own.
The main character is Robyn, a human friend of Hope's, who gets caught in the cross hairs of a supernatural issue. Adele is trying to sell herself to the Nast Cabal and leave behind the kumpania, but thinks that Robyn has some evidence that could get her in trouble. It quickly turns out that Adele is a psychopath who has no problem manipulating people and leaving a trail of bodies to cover herself.
The detective assigned to the case is a necromancer, though a fairly weak one, but he is not actually aware of the supernatural community and has never even heard the term necromancer until this novel. Given that Robin is a human and has no idea of the supernatural world, and Finn is a supernatural with no knowledge of the supernatural community, the novel is set up for a lot of confusion. For example, Paige and Karl assume that Finn is on the Cabal's payroll, and everyone else also assumes that the other characters are working for various agents and agencies. As a result of all this, there is quite some confusion which got a bit tedious.
The novel shifts between Adele, Robyn, Finn, and Hope, and like in the last novel, Hope barely has control of her powers. While her connection to Robyn was incredibly relevant to the novel, the Karl/Hope part was the least favorite part of the story for me. Oddly enough, none of the narratives are in first person, unlike Armstrong's previous novels. While I enjoyed this one, I'm looking forward to the next one which is an Elena focused novel because I need a break from Hope.