In 1840s London, Dr. Thomas Bolton [Boris Karloff] dares to dream the unthinkable: experimenting with anesthesia gases to make surgery pain-free. While doing so, his demonstration before a panel of his peers ends in a horrific mishap with his patient awakening under the knife; he is forced to leave his position in disgrace. To complicate matters, he becomes addicted to his own chemical experiments and gets involved with a criminal gang led by Black Ben [Francis de Wolff], and a ruthless killer Resurrection Joe [Christopher Lee]. Unfortunately, this shady partnership leads Dr. Bolton to further ruin, culminating in his unwitting participation in murder — for which he becomes the first victim of a blackmail scheme.
Boris Karloff
Dr. Thomas Bolton
Betta St. John
Susan
Christopher Lee
Resurrection Joe
Finlay Currie
Supt. Charles Matheson
Adrienne Corri
Rachel
Francis de Wolff
Black Ben
Francis Matthews
Jonathan Bolton
Frank Pettingell
Mr. Blount
