Professor Layton and the Eternal Diva

Puzzle expert Professor Hershel Layton and his apprentice Luke are invited to an opera by one of his former students, only to learn that most of the audience in attendance have come seeking eternal life, which has been promised to be given to a single person who successfully comes out on top after a series of puzzles. Along with the claim that a young woman who died has been reborn as a child and the search for a long lost civilisation, the mysteries run deep as Layton seeks the truth behind all the riddles.

Synopsis from Anime News Network