Robert Louis Stevenson states that his wife told him to burn the "Jekyll and Hyde" manuscript. In reality, Stevenson did burn the first draft of the story and rewrote the entire thing from scratch.
When Stevenson meets with Jekyll, he appears to be ill. In fact, Mr. Stevenson was very sick when he wrote "Dr. Jekyll and Mr. Hyde."
Robert Louis Stevenson is played by Mark Gatiss, frequent collaborator of series creator Steven Moffat.
In the flashback sequences, Dr. Jekyll's name is pronounced "Jee-kyll" rather than the more common "Jeck-yll." This alternate pronunciation was used in the landmark 1931 adaptation starring Frederic March.