The US military is running a test for a special type of radio transmitter, to be used to communicate with submarines, in a deep system of underground caves in Central America. When the signal from one of the transmitters suddenly disappears, a team of soldiers led by Major Elbert Stevens and cave specialists led by Rupert 'Wolf' Wolfsen including scientist Leslie Peterson are sent in to find out what happened. Exploring deep underground, they stumble upon a tribe of albino cave-dwellers who have apparently been isolated from the rest of the world for thousands of years. The cave-dwellers are hurt by radio frequencies and are able to see in infra-red frequencies, tracking the explorers by their body heat.
Robert Powell
as Rupert 'Wolf' Wolfsen
Timothy Bottoms
as Major Elbert Stevens
Lisa Blount
as Leslie Peterson
Anne Heywood
as Frieda Shelley
Richard Johnson
as Ben Gannon
A.C. Weary
as Lt. George Barwell
Liam Sullivan
as Lemurian Elder
Jackson Bostwick
as Hunter Prime
Richard Beauchamp
as Santos Arias
Gary Carlos Cervantes
as Hector Lopez
Dick Curtis
as Lemurian
William Gribble
as Sgt. Neumann
