Professor Layton and the Eternal Diva (レイトン教授と永遠の歌姫, Reiton-kyōju to Eien no Utahime)[a] is a 2009 Japanese animated mystery film directed by Masakazu Hashimoto, written by Aya Matsui from a story by Akihiro Hino and produced by P.A.

In the story, renowned opera star Janice Quatlane contacts her former teacher, Professor Hershel Layton, after encountering a young girl who claims to be the reincarnation of her dead friend.

While Layton and his apprentice, Luke Triton, are attending one of Janice's performances, they get unwillingly pulled into a puzzle-themed battle royal where the winner will apparently receive "the gift of eternal life".

The performance centers on the legendary lost Kingdom of Ambrosia and the secret of eternal life it holds, which will be rediscovered when its queen returns.

Once the performance is complete, a mystery man informs the audience that they are to play a game, the winner of which will receive the secret of eternal life, while the losers will die.

Back in London, Emmy Altava, Professor Layton's assistant, is meeting with Dr. Andrew Schrader when she hears about the events on the Crown Petone.

Layton finds a room filled with Melina Whistler's belongings, along with a piece of sheet music titled "A Song of the Sea".

Amelia is brought to Oswald Whistler, believed to have been eliminated by a previous puzzle, and declares her the winner of the contest, but soon forces her into a machine connected to the Detragon and confesses that there is no Elixir of Life.

Whistler had conspired with Descole to abduct girls from London and use the Detragon to implant them with his dead daughter's memories as a means of keeping her alive indefinitely.

Manga Entertainment UK has licensed the film for DVD and Blu-ray Disc release in the United Kingdom in October 2010.

One, titled "The Eternal Diva- 'Eternal Diva' Original Theme Song Collection / Janice Quatlane," featured vocal performances by Nana Mizuki and was released on December 16, 2009.

The other, titled "Professor Layton and the Eternal Diva Original Soundtrack" and featuring compositions by Tomohito Nishiura and Tsuneyoshi Saito, was released on January 23, 2010.

[6][7] Professor Layton and the Eternal Diva debuted at number 6 at the Japanese box office, grossing $1,074,959 USD during its opening weekend.

"[12] Martin Robinson of IGN gave the film a positive review stating, "It's not without faults; the climactic scene outstays its welcome, while the production levels don't match those of the top tier of anime.