This very short story is called 'a gothic novella' and was published in 1886. The plot takes place through the eyes of the lawyer Mr. Utterson, who has been a friend of Dr. Jekyll for years.
One day, Mr. Utterson was walking on the street behind Dr. Jekyll's house. This house was connected to the back of Dr. Jekyll's house. A man, coming out of the house, knocked over a child on the street, and Mr. Utterson chased him. When he looked into this man's face, he was sick. The man's eyes were lifeless and cold. His mouth was twisted. Looking at him gave Mr. Utterson a sense of horror.
And so, of course, this man was Mr. Hyde who is the evil part of Dr. Jekyll. Dr. Jekyll had done chemical experiments that resulted in his ability to change from the kind Dr. Jekyll to the monstrous Mr. Hyde. He was able to separate good and evil.
Robert Louis Stevenson was bedridden at the time of writing this story and was inspired by a nightmare. He wrote the story in three days, then took 6 weeks to refine it.
Robert Louis Stevenson
Stevenson was sick most of his life and I was interested in reading the story of his life in "Under the Wide and Starry Sky" by Nancy Horan. Check it out here.
Stevenson only lived to age 44, but he wrote many books, short stories and poetry.
The books that remain popular are "Treasure Island", "Kidnapped", and "Dr. Jekyll and Mr. Hyde".