The story is set in a fictional town called Cloisterham, which is believed to be based on Rochester. It begins as John Jasper is leaving a place in London where opium (a powerful drug) is taken by lots of people. Jasper leads a choir (group of singers) in a large church in Cloisterham. The next day Jasper is visited by his nephew Edwin Drood. Edwin tells Jasper he is worried about getting married to a girl called Rosa Bud. He has to get married to her because his parents and Rosa’s parents said they had to.