When the cable breaks on their diving bell four people find themselves trapped in a hidden underwater world.

Connie Hayward mounts an expedition into the Himalayan Mountains looking for her brother, who has not returned from a previous trek trying to locate the Yeti, or "Abominable Snowman". Arriving at her brother's last-known camp Connie and her companions find only a strange old guide, Varga. They are soon attacked by gigantic Snowmen but are not half as surprised as when Vargas reveals his secret origin and the plans he has for Connie.