The Winner's Kiss by Marie Rutkoski

The last book in the breathtaking Winner's trilogy is an irresistible story of forbidden romance and class warfare. Fans of Sarah J. Maas and Victoria Aveyard will swoon

Following the intrigue and danger of The Winner's Curse and the revolution and romance of The Winner's Crime, Kestrel finds herself in the tundra's mines and Arin has sailed home. The empire seems unstoppable.
Lies will come undone, and Kestrel and Arin will learn just how much their crimes will cost them in this third and final installment in the heart-stopping Winner's trilogy.