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 his daughter. Receiving little help from the law, Professor Zelen, an expert in the occult, is called in to assist with their investigation.
Lionel Barrymore
Professor Zelin
Elizabeth Allan
Irena Borotyn
Bela Lugosi
Count Mora
Lionel Atwill
Inspector Neumann
Jean Hersholt
Baron Otto
Henry Wadsworth
Fedor Vincente
Donald Meek
Dr. Doskil
Jessie Ralph
Midwife
Ivan F. Simpson
Jan
Franklyn Ardell
Chauffeur
Leila Bennett
Maria
June Gittelson
Annie
Carroll Borland
Luna
Holmes Herbert
Sir Karell Borotyn
Michael Visaroff
Innkeeper
