Embrace the Night by Karen Chance

Cassandra Palmer is a Clairvoyant, and the world's chief Clairvoyant at that, known as the Pythia. Cassie's elevation came as a shock to the magical world, and has caused a lot of fighting over her because she was raised in a court of vampires, and the mages and vampires don't trust each other a great deal.

But Cassie has other problems, including a geas that keeps her tied to Mircea, the vampire she loves. It was supposed to keep him tied to her until he dissolved it by having sex with her... after she came into her power, but a recent time-jaunt using the powers of the Pythia have mutated the spell so that it is doubled. This doubling of the spell has made it incredibly strong, and if Cassie can't have it banished or counterspelled, it could drive her or Mircea mad. Now, Cassie, along with her mage protector and mentor Pritkin, are in search of the one book that holds the counterspell to the geas, the Codex Merlini.

As the name implies, the Codex was written by Merlin himself, and in addition to containing a copy of the spell to release the geas, it also contains another spell that will give the mages... or anyone else who possesses it, ultimate power. So Cassie's search for the codex is attracting a great deal of magical attention. Not only from the other mages, but also from the King of the Dark Faerie Court, who she has agreed to help in exchange for the King helping hide a wounded vampire friend of hers in his Otherworldly Kingdom.

But now Cassie's foes have come up with a new plan to get Cassie to surrender herself to them, by kidnapping an old friend of hers in hopes that Cassie will charge in to save her friend the same way she did another friend from the Vampire Council's torture at the end of the last book. Cassie is alerted to this when a crowd of children show up at Dante's Inferno, the Casino where she works and lives.

She quickly discovers that the children all have strange powers that will lead to them being killed or dissected by the mages, including a Null, a Jinx, and a firestarter. Mage tolerance of those with such powers is extremely low, and many of them would or could be killed if not for the efforts of Tami, Cassie's old friend, who just so happens to be a Null herself, and who took Cassie in when she ran away from the vampires a long time ago. After Cassie eventually went back to the vampires, she returned a year later to find Tami, but Tami and the others were gone from where they had lived, and Cassie could never find them.

Eventually, it becomes clear that the Codex is not someWHERE, but SomeWHEN. It is said that Merlin aged in reverse, but the actual fact is that Merlin, like Cassie's mentor Pritkin, is half-incubus. When he wrote the Codex, he enspelled it so that if it ever left his hands, it would slowly unwrite itself, making it eventually useless to the one who stole it from him. Since it was stolen by Black Mages in Paris in the 1780's, Cassie must go back in time to retrieve it, using the powers of the Pythia.

Since Mircea has been imprisoned because the geas is slowly driving him crazy, and the Vampire council is adamant that she take one of its members with her to retrieve the Codex, she gets around their restrictions by going two weeks into the past and taking the Mircea of that time back with her into 1780's Paris. There, they attend an auction where the Black Mages are auctioning off the Codex to various powers among the vampires and mages.

But this leads to new problems. As Mircea is now hundreds of years older, his power level has increased, and this is apparent to the other vampires. Also Merlin isn't taking the theft of his Codex lying down, and as the only half-incubus ever, he's got more than enough powers to get it back. And only Cassie and Mircea stand in his way. But when he confronts Cassie over the theft of his book, she is suprised to find that she recognizes him! But back at home, Cassie is attacked by Pritkin's father, the Incubus, who also wants to find the Codex. With so many people wanting it, can Cassie keep it from falling into the wrong hands? And most of all, can she find a way to undo the Geas spell holding her and Mircea captive before it either kills them or drives them both crazy?

I loved this book, and I love this series. Cassie's slowly multiplying problems never feel pushed onto her, but are integral to the story. As she careens from one disaster to another, barely avoiding the traps laid out for her by others, she sets up other problems for herself that she can only get out of by entering another situation that will cause more problems for herself in the future. You might think that being a precognitive Clairvoyant would ease some of these problems for her, but not so. Even as the most powerful Clairvoyant in the world, she is unable to see her own future clearly, or in anything more than short visions, keeping her mired in problems of her own making.

But the way she feels about Mircea is the one good thing in this series, and even though he is a fairly ruthless vampire, it is clear that what he feels for Cassie comes from the heart. He treats her with a gentleness and love that is lacking in his dealings with others, and even though he is the one who set the geas in the first place that is causing him and Cassie so much trouble, he is also instrumental in helping her break it, and helping her get the Codex which contains the spell she needs to break the geas. Even if it does require some massaging of the conditions that allow the curse to be broken.

Despite having lots of problems, Cassie never comes off as weak or a whiner. Even though she comes up lacking in the martial arts, and needs guarding by those who can fight and defend her better, she does take classes to make herself better at fighting and sets out to defeat her problems with some confidence that she will be able to do so. This is a great book, and the series is well-worth reading. Try it and see!