Jon Pertwee and Ingrid Pitt (who plays Galliea) worked together before, in 1971 in an episode of "The House That Dripped Blood". He played an actor playing a vampire, she played an actress portraying a vampire but turns out to be a vampire for real!
Ann Michelle was originally cast as Lakis but was replaced due to her unreliability during rehearsals.
This episode was watched by 6 million viewers on its original transmission.
This episode takes place in Atlantis in circa 1500 BC.