The crew of the Calico journey into the Himalayan Mountains with a scientific expedition led by Dr. Darian's old friend and colleague, Dr. Rourke, in search of a reputed source of geothermal energy.
After approaching an area near a dormant volcano, which they believe to contain the energy source, they find the Great Watchuka, who attempts to crush the crew by setting off an avalanche. Godzilla is called and arrives to shield the group from the falling snow with his own body. Entering the volcano, the Calico crew discovers a village ruled by a race of very intelligent human-sized hominids covered with white fur who call themselves the Watchuka. The Watchuka were the source of the legends of the abominable snowmen reported by the people of Tibet for ages, and their village is powered by a steam engine that turns out to be the origin of the geothermal energy source the party was searching for.
As it turns out, the Watchuka resent the human race who dominate the world, and they plan to conquer the surface by releasing an army of larger warrior snow monsters who have been kept in frozen storage until war is announced. The crew oppose the Watchuka's plan, but the villagers summon their guardian, the Great Watchuka, to stop the Calico crew from escaping spreading a warning about the upcoming invasion. The Watchuka clutched Quinn in its hands as she summoned Godzilla.
Godzilla arrived, and the two kaiju began to fight. After wrestling with the Great Watchuka, Godzilla used his fire breath on the monster but it used a giant boulder to block the fire. As they kept fighting, the stresses of their fight reawakened the dormant volcano. As the volcano showed signs of eruption, the ground fissured, Godzilla dodged one of the Great Watchuka's tackles, sending the Watchuka off the side of the cliff to disappear into a chasm. Godzilla saves the crew from an eruption and seals the volcano with a giant rock, imprisoning the Watchuka inside.