When a mining company wishes to expand its operations into a remote west coast valley, archaeologists are sent to clear the site by excavating the historic graves of a missionary family that settled there in the 1850s. Local legend tells that the preacher degenerated into madness and shot his wife and children before killing himself. When archaeologist Jane Anson uncovers the skeletons however, she finds that there was more to the killings than madness, as the grossly deformed skeletons show that these settlers had played host to a vicious parasite. Cut off in the forest and obsessed with solving the mystery of their deaths, Jane begins to question her own sanity as she and her team members appear to succumb to a gruesome illness. Is this disease of the mind, or are they being colonised by a more ancient life force – one that has its own hunger to survive?