Santiago, a jolly modern bandito, has just lost his partner when he happens on the isolated farm of young Manuel and Maria Lopez...

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.

Drunk and disillusioned Roman, Marcellus Gallio, wins Jesus' robe in a dice game after the crucifixion. Marcellus has never been a man of faith like his slave, Demetrius, but when Demetrius escapes with the robe, Marcellus experiences disturbing visions and feels guilty for his actions. Convinced that destroying the robe will cure him, Marcellus sets out to find Demetrius — and discovers his Christian faith along the way.