After inheriting a farm on New Zealand’s South Island, Lewis Harding tries his best to keep it running. The financially strapped farmer is forced to forage his new land for implements, eliciting the help of his son Gary. But when they go too close to the entrance of an old deserted gold mine, catastrophe strikes in more ways then one. When Gary’s older brother, Dr. Cecil Harding, shows up at the farm, Nekenhalle, he discovers that his brother and father had gone missing. 

A spate of livestock mutilations plague the local area, forcing Dr. Harding, a veterinarian, to call in the help of the Australian Wilderness Society. Ironically, this coincides with their current investigation of culling by poison, because, according to Harding, the New Zealand livestock are dying of snakebites. Knowing that New Zealand does not have snakes, the Wilderness Society obtains the help of Scottish explorer David Purdue during a legal debate.

Purdue and his associates, journalist Sam Cleave and historian Dr. Nina Gould, accompany the Wildlife Society under the pretense of making a documentary, while actually seeking the location of the Lost City. Similar poisonings in the remains of Nazi soldiers prompted Purdue’s pursuit into the Lost City’s secret, but Nekenhalle has a reputation for evil.

Inside the bowels of the farm, the expedition party finds the source of the killings, but at the same time, they venture into a forbidden place they do not know the way out from....