Oak King Holly King

Shrike, the Butcher of Blackthorn, is a legendary warrior of the fae realms. When he wins a tournament in the Court of the Silver Wheel, its queen names him her Oak King - a figurehead destined to die in a ritual duel to invoke the change of seasons. Shrike is determined to survive. Even if it means he must put his heart as well as his life into a mere mortal's hands. Wren Lofthouse, a London clerk, has long ago resigned himself to a life of tedium and given up his fanciful dreams.
When a medieval-looking brute arrives at his office to murmur of destiny, he's inclined to think his old enemies are playing an elaborate prank. Still, he can't help feeling intrigued by the bizarre-yet-handsome stranger and his fantastical ramblings, whose presence stirs up emotions Wren has tried to lock away in the withered husk of his heart. As Shrike whisks Wren away to a world of Wild Hunts and arcane rites, Wren is freed from the repression of Victorian society.
But both the fae and mortal realms prove treacherous to their growing bond. Wren and Shrike must fight side-by-side to see who will claim victory - Oak King or Holly King.