The Contract Between a Specter and a Servant novel volume 3 was written by Michiru Fushino.

Just when Masamichi thinks he's getting used to life as the servant of a specter, the rug gets pulled out from under him. Bougyoudou has a new client in need of Shino's more mystical skill set, and it turns out he'll have to go overseas! Before Masamichi can figure out how to keep himself busy while his master is away, he finds himself taken along on a trip to England. A change of scenery might be just what he needs to reassess his goals in life, even if a haunted house isn't an ideal destination. However, with malicious spirits around, there is much more in store for him than travel adventures and self-reflection.