Inspector Mulrooney was a Scotland Yard inspector sent to Engerfield, England from London to solve the murders of Stephen Banning and Joseph Whemple. A very practical man prone to skepticism, Mulrooney did not believe John Banning's claims that a living mummy had killed his father and uncle. Mulrooney was certain that "facts, not fantasies" would solve the case, but the deeper he dug into the mystery, the less certain he became that a mortal killer was responsible for the crimes, until at last the Inspector was forced to accept John's testimony. Especially when he encountered the mummy himself, Kharis. Despite being hit over the head by the powerful undead assassin while acting as the bodyguard of John and his wife Isobel Banning, Mulrooney survived. He and John later pursued Kharis to the swamp where Mulrooney and several deputized men blew the mummy away in a hail of gunfire.