Sir Borotyn, a prominent Prague resident, is discovered murdered in his home, with all indications pointing to a vampire assault. The victim's friend, Baron Otto, and the physician who analyzes the body are certain that the vampire is the mysterious Count Mora, or perhaps his daughter, but receive little help from the law. Professor Zelen, an expert in the occult, is called in to assist with the investigation.
A little girl goes in search of her father who is reported missing by the military during the Second Boer War.
In a Scottish sanitarium, a brilliant research psychiatrist works on a treatment for dementia praecox. He falls for his altruistic female lab assistant and they begin a passionate, tragic relationship.
