Witchfinder: The Gates of Heaven (Witchfinder: The Gates of Heaven #1)

A series of occult events mystifies the man known as the Witchfinder, but even more surprising is the revelation that he is not alone in exploring the paranormal in London. When a personal invitation arrives from the palace, Sir Edward Grey is pulled even deeper into underground supernatural exploration alongside new allies in the race to stop a mad scientist from destroying London in his pursuit of mystical power.