Book of Masks — Nathalie Gray

Jasmine Dunmore travels to Italy to inspect and sell a house that she has inherited in Venice. She doesn't suspect that the house is already home to a host of demons.

Lumere is The Hermit. He is the only one who can keep his demonic brethren in their own plane, and out of the mortal one, where they would bring about Armageddon.

Together, he and Jasmine must keep Vespero The Devil from getting the last key that will allow the door between the demonic and mortal worlds to be opened.