Review by Dethcharm

When an explorer goes missing, a team is assembled to track him down, leading to the dreaded "Cave of Death". On their way, they encounter the bizarre Dr. Ramsey (Gerald Milton). He's a scientist of the mad variety, who also cans his own fruit. Ramsey is working with local fungi. He's very enthusiastic about his work.

We soon discover that something sinister and unnatural is going on.

THE UNKNOWN TERROR sort of plods along, becoming a caving adventure / rescue mission. This goes on up until the final revelation of the "terrible truth". Is it worth the wait? Well, not really. That is, unless gurgling soap bubbles freak you out. To be fair, they're somewhat effective in a low-low budget way.

Recommended for sci-fi fans who love sentient sludge and / or seeping slime...