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.
Unfortunately the movie What Waits Below is not yet available on HBO Max.
| Directing | Don Sharp | Director |
| Production | Sandy Howard | Producer |
| Production | Robert D. Bailey | Producer |
| Production | Jim Garrard | Casting |
| Art | Stephen Marsh | Art Direction |
| Production | Mel Pearl | Executive Producer |
| Production | Victoria Plummer | Production Coordinator |
| Sound | Michel Rubini | Original Music Composer |
| Editing | John R. Bowey | Editor |
| Writing | Freddie Francis | Story |
| Production | Don Levin | Executive Producer |
| Sound | Denny Jaeger | Original Music Composer |
| Production | Jeffrey M. Sneller | Associate Producer |
| Costume & Make-Up | Pamela Hallisey Hiss | Makeup Artist |
| Crew | Clarke Coleman | Stunts |
| Writing | Robert Vincent O'Neil | Screenplay |
| Camera | Virgil L. Harper | Director of Photography |
| Crew | Mike Bledsoe | Stunts |
| Crew | Ron Bledsoe | Stunt Coordinator |
| Writing | Christy Marx | Screenplay |
| Sound | David Lee | Sound Mixer |
| Sound | Craig Felburg | Sound Mixer |
| Crew | Bret Culpepper | Special Effects |
| Crew | Doug Bledsoe | Stunts |
