In "The Phantom of the Opera" as Christine is giving her final performance of Faust, the Phantom or Erik, kidnaps her while she is singing a particularly moving aria. The aria is one in which she asks the angels to take her to heaven. It is appropriate that Erik, or Christine's own Angel of Music, comes to take her at that moment. Though Raoul follows Erik and Christine with the help of the Persian, he ends up in a torture chamber.
Soon after, Erik raises his voice at Christine. He is furious and accuses an already mentally exhausted Christine of lying and of betrayal. If she does not marry him, he plans on ruining the Opera Garnier. Though Christine accepts and soon begins to show empathy toward Erik, he feels remorse for what he has done and he lets Christine and Raoul go free. However, Erik does hold Christine to a promise that she come back after he dies to bury him with the ring he gave her.
in Sir Andrew Lloyd Webber's adaptation, in the end of the play, he gives Christine his ring. The ring was given to her by Raoul in which he gave it to Christine in New Year (Because they have this 'Bal Masque' or Masked Ball) It is an engagement ring. During the end of the song "Masquerade" the Phantom shows up and steals the ring that Raoul gave Christine. And thus,it's already his ring! Since he said Your chains are still mine you will sing for me!/ you belong to me!