Before he joined the police, William Monk worked as a banker under Arroll Dundas, who became Monk's mentor and taught him how to behave and dress like a gentleman. When Dundas was wrongly convicted of railway fraud, Monk decided he would never again be so powerless against injustice, so he became a policeman. He was ruthlessly ambitious and quickly climbed the career ladder—while making many enemies along the way. He had a coach accident in 1856, after which he lost his memory—a fact he kept secret to save his job. After the accident he met Hester Latterly, a Crimean War nurse and they became close, with her the only one who knew about Monk's memory issues. The Monk mysteries are set in the Victorian era (1850s-1860s).