The first cinematographic adaptation of the infamous Count Cagliostro. The alchemist Athlotas foretells that his student, Cagliostro, will meet a gypsy named Lorenza. After a duel over her, Cagliostro takes Lorenza home and uses her exceptional medium powers to achieve immense fame. At court, he reluctantly predicts Marie Antoinette’s execution. Subsequently arrested, his bitter rival, Chevalier d’Oisemont, accuses him of witchcraft, driving Cagliostro to poison himself in his cell.