The Sign of the Four Sir Arthur Conan Doyle

Television and film

There have been multiple film and television adaptations of the book:

Radio

A radio adaptation of the story was broadcast on New York radio station WGY on 9 November 1922. The cast included Edward H. Smith as Sherlock Holmes, F. H. Oliver as Dr. Watson, and Viola Karwowska as Mary Morstan. It was produced as part of a series of adaptations of plays, so it is likely that the script was based on an existing stage adaptation of the story (one was written by John Arthur Fraser in 1901 and another by Charles P. Rice in 1903).[7]

A six-part adaptation of the novel aired in the radio series The Adventures of Sherlock Holmes. Adapted by Edith Meiser, the episodes aired from 9 November 1932 to 14 December 1932, with Richard Gordon as Sherlock Holmes and Leigh Lovell as Dr. Watson.[8]

The book was adapted by Felix Felton for the BBC Light Programme in 1959. Richard Hurndall played Holmes and Bryan Coleman played Watson.[9]

In 1963, the story was dramatised by Michael Hardwick for the BBC Home Service as part of the 1952–1969 radio series, with Carleton Hobbs as Holmes and Norman Shelley as Watson.[10]

CBS Radio Mystery Theater aired a radio version of the story in 1977, starring Kevin McCarthy as Holmes and Court Benson as Watson.[11]

The Sign of the Four was adapted for radio by Bert Coules in 1989 as part of BBC Radio 4's complete Sherlock Holmes 1989–1998 radio series, with Clive Merrison as Holmes, Michael Williams as Watson, and featuring Brian Blessed as Jonathan Small.[12]

In 2016, the story was adapted as an episode of the American radio series The Classic Adventures of Sherlock Holmes, with John Patrick Lowrie as Holmes and Lawrence Albert as Watson.[13]

Stage

Paul Giovanni's 1978 play The Crucifer of Blood is based on the novel. The Broadway premiere featured Paxton Whitehead as Holmes and Timothy Landfield as Watson. The 1979 London production featured Keith Michell as Holmes and Denis Lill as Watson.