Theophilus Monk used to be Nicholas Brisbane’s school master. When he was expelled from school, Monk went with him and has looked after him ever since. He is referred to a Brisbane’s factotum or majordomo.
Monk has helped to administer various treatments to Brisbane for his headaches, none of which has been entirely successful.
When a delirious Brisbane locks himself in a room with Julia and passes out on her, Monk feels responsible and and explains their history to Julia. He is grateful that she doesn’t hold the incident against him and doesn’t mention what happened to Brisbane.