Jekyll is a rich young man, fond of the study of occult science. In the course of his studies in his laboratory, he discovers a medicine that has the power of completely changing both the mental, moral and physical makeup of a man. He experiments with this medicine and discovers that he at once becomes another personality, Hyde. In his new form he is hideous physically and debased morally. He also discovers an antidote to the medicine that brings about these changes. While in the Hyde form he commits all manner of horrible outrages so that the whole city of London rings with the news thereof. Dr. Jekyll, while in his natural form, that of a cultured, charming young man, is horror-stricken by the brutalities which he commits in the other form. Ere long the medicine at last begins to have an extraordinary effect, the changes taking place without the volition of Jekyll. In order to protect himself from being seen by any one in his beastly form, he locks himself in his room, when he feels the change about to take place, and with the aid of an old servant sends for the antidote to bring him back to his original form. He is engaged to a charming young lady, Maud, who is terribly grieved at his extraordinary conduct in the way of disappearance. Whilst in the form of Jekyll, he goes to his solicitor and makes arrangements that Hyde shall be his heir, so soon as the transformation again takes place he presents himself in his Hyde form to his solicitor. He is guilty of terrible outrages, becomes a fugitive from justice after which he is caught and attempts to make peace by the giving of a large check. Unfortunately the signature is not that of Hyde but of Jekyll. Whilst in his Jekyll form his fiancée and friends are horrified by seeing him change before their eyes into the murderer Hyde. The last scene shows Dr. Jekyll struggling with a nightmare in his chair and awakening in the presence of Maud, thank God it was all a dream.