Ahhh Sebastian! *swoons* He is the perfect man. Old-time gentleman, shy, knows what he wants and fights for it, just... perfect! I wish I had my own Sebastian!
OK, so now that I got that out of the way... Kaderin is a valkyrie and she's been "cursed" with not being able to feel for a thousand years, since the death of her sisters, who were killed by a vampire. She is tough (as all valkyrie are), loves and lives to kill vampires and for the Hie (like the Amazing Race). That whole concept was new and interesting. Kaderin always enters (and wins) this race and this year is no different. Well, except for the fact that before it starts she hears of a vampire in a castle and goes there to slay him, but realizes that she can't. She is his Bride, and because of him, after so long, she starts to feel again. She in turn wakes him from years of misery.
Sebastian is Nikolai Wroth's brother. He was turned by Nikolai against his will and has hated being a vampire during his whole existence. He just wishes for final death. And Kaderin is the one supposed to bring it to him, which he is fine with, until he realizes she's His. The one for him. His Bride. And he will do anything to have her, protect her, cherish her, and live eternity with her.
While Kaderin has to compete in the Hie, Sebastian enters as well, with the intention of wining for her. The prize seems to be something she wants above all other things. A key to go back in time twice. He doesn't think it could work, and he doesn't know why she wants to get it, but he is determined to help her or win it for her. They have some competition, and some tough competition in the form of Bowen, the lykae who we met in the previous book, and who wants the key to go back in time and rescue his dead mate.
There's a lot of action, intrigue, and some pretty amazing sexual tension and eventually, yes, pretty amazing sex. And even though Sebastian is not a virgin, he's not the most experienced in that department so it's up to Kaderin to teach him, which he learns quickly, and to be his first in many things.
Their relationship develops perfectly. It's not the "I'm in love" at first sight, their love develops from constantly being together, liking each other, their company, their support. Even though there were no major events in the overall world for this series, this was an excellent book and I'll be looking forward to reading the next one soon!