In the undersea city of Rapture, Booker DeWitt is a well-known private investigator who handles his clients' dirty work between bouts of drinking and gambling. On New Year's Eve, 1959, a mysterious woman named Elizabeth hires him to look into the disappearance of a young girl called Sally — though her motives are murky and she reveals little, saying only that Sally is alive and that the celebrated artist Sander Cohen may know where she is. Journeying to Cohen's club on High Street, the pair are turned away for lack of the exclusive masks worn by his party's guests. So, with Elizabeth distracting the local shopkeepers, Booker slips away to retrieve the required mask — and the two are at last welcomed into Cohen's party.