Dante Valentine is a necromance, a special type of Psion that can cross the barriers of death and contact the spirits of the dead. A few years ago, she accepted a job from Lucifer, to retrieve something for him, and was given a shadow, a fallen demon named Tierce Japhrimel. Danny and Japh came to care for each other deeply, and he made her his Hedaira, which gave her some of his power and made her physically tougher and more powerful. Mentally, however, she remains the same.
Much happened to Danny. She found out her friend Doreen had borne a child, but the child was part demon. It was to be used by the government for experimentation. Both Lucifer and the Hegemony government wanted the child, a girl named Eve, for her ability to procreate. Since Lucifer controls his demons ability to procreate, granting it only to whom he pleases, Eve was a threat to his power.
Now, only a few years later, Eve has grown to adulthood, and begun rebelling against Lucifer. Danny and Japh have tried to stay out of the conflict as much as possible, but because Japh is an extremely powerful demon, and used to be Lucifer's Right Hand and Assassin, both sides have come courting him and Danny.
As "To Hell and Back" starts, Danny has been released from Hell after having been kidnapped to and tortured there. She's a mess, and despite her being part demon thanks to Japh, she is extremely fucked up physically. Japh has been searching for her, going after and attacking anyone who might know anything about where Danny is, and he's extremely angry to boot. When one of his agents finds her, he's finally angry enough to rebel on his own against Lucifer, which requires a very special knife that was created by Fallen Demons and their Hedairas for just such an occasion. It can kill any demon, including Satan himself, and only someone who is human or mostly human (like a Hedaira) can wield it. He takes Danny in search of the two halves of it, keeping her close to ensure Lucifer cannot take her again.
But both Lucifer and Eve have been waiting for this to happen. Who will Danny trust enough to side with? And is either even worthy of her trust? Or for that matter, is Japh, who won't tell her anything and apparently only tells her lies? One thing is for sure, no matter who wins, great changes are coming to Danny Valentine's world.
This was a great book and makes a great ending to the series. The book teases readers about the nature of the Fallen Demons and their Hedaira, but due to the nature of demons themselves, we can't trust any answers we are given, since, as the book tells us, it is in the nature of demons to lie. And they all lie. Danny herself falls victims to many lies in the book, and in fact, many of the lies lead her to make dangerously destructive mistakes. And this time, the outcome affects not only her and Japh and those who depend on her, it will affect her entire world.
Lilith Saintcrow has a wonderfully creative mind, and it's on full display here. The psions of this world are more like witches and wizards than actual psychics. Necromancers have traditionally been wizards who deal with raising and making people or things undead. Magi do spells. But She introduces Skinlins, who work with plants and plant DNA, Sedayeen, healers who are bound to complete pacifism because they feel the pain of others, Animones, who heal and connect with Animals, Sexwitches, who raise power through the act of sex, and others. In addition to the standard Nichtvren (Vampires) and werecains (lycanthropes), there are Koboldings, Goblin-like creatures, Swanhilds, avian-like creatures with hollow bones and poison flesh. And among humans, Sk8's, which are tribes of teenagers who live on the streets riding slicboards or skateboards that run on anti-gravity. Her future universe is gritty and more than a little distopian, especially with what is revealed in this last book, though the author herself declines to categorize her world.
Dante herself could come off a bit Mary-Sueish except for the fact that she is extremely abrasive and more than a little mentally fragile, even though she has access to Japh's power physically. Yes, she's strong and can come back from just about anything, more or less, her mind is much weaker and can be cracked fairly easily. Sometimes, such as when she is savaging her friends or allies with her tongue, she can be very hard to like, and it's a wonder than anyone stays around her. But then, given that she would lay down her life for her friends, and she can't resist anyone who really needs her lets you know why she has such good friends in the first place.
This series isn't for everyone, and may not be to your taste, but it's worth giving it a try to see such a huge, detailed, and believable world. Dante Valentine may be an acquired taste, but once you acquire it, it's hard to stop wanting more.