In the depths of an ancient forest, something has been growing. Something older than humanity itself, and perhaps greater too. When a park ranger discovers a man and his son living wild, she stumbles onto a secret that is about to change the world.

Five vacationers and two crewmen become stranded on a tropical island near the equator. The island has little edible food for them to use as they try to live in a fungus covered hulk while repairing Kessei's yacht. Eventually they struggle over the food rations which were left behind by the former crew. Soon they discover something unfriendly there...

A woman leads an expedition into a remote jungle to find her long-lost brother, but instead finds a mad scientist who has created a fungus monster that feeds on the local inhabitants.