The Novella's impact is such that it is had become a part of the language, with the very phrase "Jekyll and Hyde" entering the vernacular to refer to people with an unpredictbly dual nature: usually very good, but sometimes shockingly evil instead.

The novel focuses on John Utterson, a lawyer and friend of Dr. Jekyll and it begins with John Utterson talking with his other friled, who has just witnessed an odd situation.

A man identified as Edward Hyde ran over a girl, only to pay off her family later with a check from Dr. Jekyll.