After a detective is assaulted by thugs and placed in an asylum run by Professor Baum, he observes the professor's preoccupation with another patient, the criminal genius Dr. Mabuse the hypnotist. When Mabuse's notes are found to be connected with a rash of recent crimes, Commissioner Lohmann must determine how Mabuse is communicating with the criminals, despite conflicting reports on the doctor's whereabouts, and capture him for good.
The mysterious Count Orlok summons Thomas Hutter to his remote Transylvanian castle in the mountains. The eerie Orlok seeks to buy a house near Hutter and his wife, Ellen. After Orlok reveals his vampire nature, Hutter struggles to escape the castle, knowing that Ellen is in grave danger