Winter of Ice and Iron by Rachel Neumeier

In this gorgeous, dark fantasy in the spirit of Jacqueline Carey, a princess and a duke must protect the people of their nations when a terrible threat leaves everyone in danger. With the Mad King of Emmer in the north and the vicious King of Pohorir in the east, Kehara Raehema knows her country is in a vulnerable position. She never expected to give up everything she loves to save her people, but when the Mad King’s fury leaves her land in danger, she has no choice but to try any stratagem that might buy time for her people to prepare for war–no matter the personal cost. Hundreds of miles away, the pitiless Wolf Duke of Pohorir, Innisth Eanete, dreams of breaking his people and his province free of the king he despises. But he has no way to make that happen–until chance unexpectedly leaves Kehara on his doorstep and at his mercy. Yet in a land where immanent spirits inhabit the earth, political disaster is not the greatest peril one can face. Now, as the year rushes toward the dangerous midwinter, Kehera and Innisth find themselves unwilling allies, and their joined strength is all that stands between the peoples of the Four Kingdoms and utter catastrophe.