Sherlock Holmes: A Drama in Four Acts is a stage play co-authored by Arthur Conan Doyle and actor William Gillette, bringing the famous detective to life on the late Victorian stage. In this original story (set in 1880s London), Sherlock Holmes faces off against criminal mastermind Professor Moriarty while juggling a delicate romance and protecting a young woman from peril. The play condenses several Holmes adventures into one suspenseful narrative, featuring iconic elements like the Baker Street sitting room, fiendish traps set by Moriarty, and Holmes's dramatic disguise and escape at a foggy moor. Gillette, who also portrayed Holmes on stage, infused the script with action, humor, and even the immortal line, "Oh, this is elementary, my dear Watson." The drama was wildly popular, solidifying Holmes's image (deerstalker, pipe, and all) in the public imagination. As a published script, it offers a unique, theatrical take on Holmes, full of derring-do, comedic asides by Dr. Watson, and the ultimate triumph of good over evil under the footlights.

Sir Arthur Conan Doyle (1859–1930) was a Scottish author, physician, and spiritualist best known for creating the legendary detective Sherlock Holmes. Born in Edinburgh, he studied medicine at the University of Edinburgh, where his storytelling talent began to emerge alongside his scientific education. Though initially practicing as a doctor, Doyle turned to writing to support himself, eventually achieving worldwide fame with the publication of A Study in Scarlet in 1887. Beyond detective fiction, he explored historical novels, science fiction, and supernatural themes, notably in the Professor Challenger series. A passionate advocate for justice, he was involved in several real-life legal investigations. In his later years, Doyle became deeply involved in spiritualism, dedicating much of his time and writings to life after death. His legacy endures as one of the most influential figures in literary history.