K.L. Noone 
In the Pass of Ghosts [EPUB ebook] 

Ghosts are real. And now they’re Aric’s problem.Even legendary swordsmen need time off, and Aric and his half-fairy partner Emrys are traveling south to visit Aric’s brother. But, on a stormy night at a roadside inn, an old friend stumbles in nearly frozen, swearing that the mountain pass is haunted … and deadly.With travelers and friends in danger, Aric and Em will try to solve the mystery of the murderous hauntings, but that won’t be simple. Swords aren’t much use against specters. Any use of Em’s magic will draw attention from a powerful fairy king. And this quest is making Aric think about his past, his future, and settling down in one spot with Em, someday … if Emrys wants that future, too.