Elizabeth Bear 
Whiskey and Water [EPUB ebook] 

Several years ago, Matthew the Magician ended an age-old war. It only cost him everything — and everyone — he knew and loved. Turning against his mentor, Jane Andraste, in the realm of Faerie left him physically crippled and his power shattered. But Matthew remains the protector of New York City. So when he finds a young woman brutally murdered by a Fae creature, he must bring her killer to justice before Jane uses the crime to justify more war-and before he confronts an even larger threat in the greatest Adversary of all . . .