Under the Gaslight follows the perilous journey of virtuous Laura Courtland: raised as a daughter of Society, she discovers on the eve of her marriage to upstanding veteran Ray Trafford that she was taken in from the streets as a child. High society rejects her when her secret is exposed, and she hides in New York's underbelly, pursued by both her distraught fiance as well as the arch villain Byke, who is determined to exploit her secret—and others—for his own gain. Beginning in a New York salon and descending into a tenement basement, Under the Gaslight features swapped cradles and mistaken identities, society swells and street urchins, a ball at Delmonicos and a sing-along under Pier 30, and most famously a one-armed man tied to the railroad tracks. Metropolitan's production features live piano accompaniment throughout.