Which fictional detective dies in the short story "The Final Problem"?

"The Final Problem" is a short story by Sir Arthur Conan Doyle featuring his detective character Sherlock Holmes. It was first published in "Strand Magazine" under the title "The Adventure of the Final Problem" in December 1893. It appears in book form as part of the collection "The Memoirs of Sherlock Holmes". This story, set in 1891, introduced Holmes's greatest opponent, the criminal mastermind Professor James Moriarty.

"The Final Problem" was intended to be exactly what its name says. Conan Doyle meant to stop writing about his famous detective after this short story; he felt the Sherlock Holmes stories were distracting him from more serious literary efforts and that "killing" Holmes off was the only way of getting his career back on track. "I must save my mind for better things," he wrote to his mother, "even if it means I must bury my pocketbook with him."

Conan Doyle and his wife toured Switzerland and discovered the village of Meiringen in the Bernese Alps. This experience fired Conan Doyle's imagination. "In 1893 he wrote in his diary, which still exists, that he wanted to kill Sherlock Holmes at the Reichenbach Falls," says Jürg Musfeld, director of the Park Hotel du Sauvage, where Conan Doyle is believed to have stayed during his visit to the village.