Isika Tangsrichanon

A group of teenagers journeys to a remote forest in search of a friend who's been reported as lost after his trip to the forest. While searching, they are caught in a brutal wind storm which blows their vessel into the middle of the forest. The teenagers are forced to seek shelter in a dark cave where, unbeknownst to them, an unusual creature is silently resting.

While studying caves, a group of geologists leaded by Professor Maeda is attacked by gecko fiends that possess their bodies transforming them into zombies. The next morning, the local inspector finds the corpses of the team. Miss Kwan travels to that location to give lectures and is possessed by the evil gecko spirit, but her skeptical boyfriend doctor does not understand what is happening to her and believes she has suffered brain damag.