It was directed by Jacques Tourneur (his final film) and starred Vincent Price, Tab Hunter, Susan Hart and David Tomlinson.

Price is the captain overseeing a group of sailors who have lived there for more than a century where the peculiar mix of gases has allowed them to extend their lifespan.

[3] Around the turn of the century, American mining engineer Ben Harris is working on the Cornish coast in England when he finds a body washed up on the beach.

While talking to the hotelier's daughter, fellow American Jill Tregellis, and an eccentric artist, Harold Tufnell-Jones, a mysterious intruder appears but disappears.

The city is now inhabited by a group of smugglers led by the cruel and tyrannical Captain who hid down there in 1803 and due to the strange mixture of oxygen have not aged in over a century.

Dan, one of the Captain's men who wishes to leave, offers to help the two escape, provided they use their influence to secure him a full pardon for his past crimes of smuggling.

Realising that Ben and Harold are untrustworthy, the Captain decides to allow the Gill Men to sacrifice the two as a means to appease the volcano's wrath.

[6] Louis M. Heyward confirms this tension and admits to rewriting the script to add humour; in particular, he says he added the comic chicken and introduced the character played by David Tomlinson.