The film
Dr. Henry Jekyll believes that there are two distinct sides to men: one that is good and one that is evil. He believes that by separating the two, man can become liberated. He succeeds in his experiments with chemicals to accomplish this and transforms into Hyde to commit horrendous crimes. When he discontinues use of the drug, it is already too late.
Synopsis from TMDB.
The name
Also in Dr. Jekyll and Mr. Hyde
Elsewhere on screen, Pub
