Let me start by saying I listened to this as an audiobook (from audible.co.uk), and have not read it - maybe there's a difference?
This starts fast and doesn't let up for a long, long time. I found it helped to have "read" (ie listened to) the previous books in the series, but you could probably manage this as a stand-alone.
The story: Claudia Donovan is a single mum, working as a cop. We meet her and a vampire, Tiber, at a murder scene. All hell breaks loose and Claudia is betrayed by someone she trusts. She comes to in an anonymous hotel room, and a nasty ritual is carried out on her and what she thinks is another human. He turns out to be a demon, and they are bound together, the binding enabling Claudia to open the portal between Orca, homeland of the demons, and the human world, a portal normally closed to all.
Although she puts up a good fight, she is coerced into entering Orca, along with the vampire Tiber, when her daughter is kidnapped by demons.
Once there she fights back, against seemingly desperate odds, determined to rescue her daughter. She is horrified to learn that her daughter Holly is half demon and that the demons intend for Holly to stay in Orca. She also learns that humans can only survive in Orca for a few weeks - so her time is limited.
She attracts the desire of Luca, a seriously dangerous demon who claims Claudia is his destined mate, even though he also despises her and rejects the bond - humans are weak and his enemy. His entry into the story is pretty impressive! Unable to deny their bond, he mates with her, something she is powerless to stop. Given that this is essentially rape, it was carefully written and is in no way gratuitous. There's an earlier scene where Claudia is being coerced into sex that made me quite uncomfortable until it resolved in a very unexpected way that left me feeling upbeat! I half thought something similar would happen again, or that someone would rescue her - but this time it doesn't happen.
The vampire Tiber, who has his own reasons for being in Orca, wants to help her and her daughter, and his sorrow that he couldn't save her from Luca's mating is brilliantly read by the woman reading the audiobook - I hope it reads as well off the page.
They escape and nearly win through, but to get them all out alive, Claudia is forced to make a deal with Luca to save Tiber, a deal that includes her letting demons into Crimson City.
Claudia has problems - she is the beloved of one of the most powerful demons that exists, the dear heart of a renowned and powerful vampire, has a half demon daughter, and is only human. Who will she love, and which will win?
Both Luca and Tiber sound pretty stunning - I'd be hard pressed to decide and even though it is pretty clear who will win through, I had a pang of disappointment at how it was all resolved.
I loved listening to this, it is something I might get hold of in printed copy, and I'll be carrying on with the series.