"The Terror of Blue John Gap" is a short story written by Sir Arthur Conan Doyle. It was first published in Strand Magazine in 1910. It is the subject of an ongoing study, The Terror of Blue John Gap Project, by Margie Deck and Nancy Holder. The story comprises the adventures of a British doctor, recovering from tuberculosis, who goes to stay at a Derbyshire farm looking for rest and relaxation, becomes entrapped in a series of sinister events, and is forced to uncover the mysteries surrounding "Blue John Gap" and the "Terror" that lurks within it. Source: Wikipedia (en)