Crimson King: The Seven Hungers Book 1

Censured Crown sorcerer Ambrose Drake is hired to investigate a bizarre emergence in a city halfway across the world from his native London. Drake soon learns that a being from one of the Seven Hungers beneath our world is attempting to cross over. Flanked by his ex-lover and betrayer, Agent Karen Winter and a young acolyte with a severe lack of magical ability, Drake must plunge once more into the depths to save humanity.