Mortal Heart, by Robin LaFevers

The first two novels in Robin LaFevers's His Fair Assassin trilogy are intelligent, atmospheric, and jam-packed with historical detail, and the final installment, Mortal Heart, is no different. None of the books have been perfect, but this is still one of the most interesting and ambitious teen series to come out in years.

The trilogy is set in 15th century Brittany, which is clinging to its independence from France by the skin of its teeth. Each book has focused on a different girl raised at the convent of St. Mortain, the (fictional) Breton god of death. Mortain's followers are trained as assassins, and no one is better prepared than Annith, the convent's most gifted and dedicated novitiate. Inexplicably, however, the abbess decrees that Annith will become a seeress, a position that will isolate her behind the convent's walls forever. Annith struggles to accept the abbess's decision, but when a younger (and far less trained) girl is sent on a dangerous mission in her stead, she realizes she can no longer blindly follow the convent's orders.

My only major criticism of Mortal Heart is the weirdness of its romantic pairing, which features way more chemistry than logic. I can't describe the protagonists' conflict without spoilers, but trust me: even at the end of the story, Annith's relationship is facing significant, um, logistical challenges. That being said, romance is only one aspect of this book, and I was easily able to overlook a little hot-but-bizarre relationship drama in favor of the novel's many other strengths: the complex historical intrigue inspired by Anne of Brittany's fight for Breton independence, the constant action, and the intense sisterly bond between LaFevers's intelligent, powerful, and sympathetic heroines.