The names Ridley, Ripley and Nostromo are references to the classic horror film 'Alien.' This is what Jonathan means when he says "I know what her favorite movie is." Later Jonathan references the film's tag line "in space, no one can hear you scream."
The musical is based on a crime novel by Gaston Leroux. His most famous novel, 'The Phantom of the Opera' was made into one of the longest running West End and Broadway musicals of all time.