Four balloonists and their dog are stranded on a remote island with a woman believed to be a descendant of Frankenstein, who is conducting experiments on lost sailors.

Robert Clarkeas Dr. Hadley
Steve Brodieas Jocko
Cameron Mitchellas Clay Jayson
Andrew Dugganas The Colonel
John Carradineas Dr. Frankenstein
Katherine Victoras Sheila Frankenstein van Helsing