Synopsis (Part 1)
Tantor drinks from the nearby river and accidentally contaminates himself with some sort of poison that has polluted the river. After analyzing it, Professor Porter concludes that it must have come from up the river, and so Tarzan and his friends convince Dumont to allow them to borrow his boat, as the poison will destroy his trade and jungle life. Terk stays behind with Tantor to look after him, while the others travel upriver, only to have their boat blown up by pressure caused by sick hippos and bad rapids. Going ahead on foot, Tarzan encounters Basuli, son of Chief Keewazi of the Waziri tribe, who tell them that men who resemble Jane and the Professor dug in the mountainside and dumped deadly chemicals into the river water. Meanwhile, Tantor has recovered from his illness and with Terk goes after his friends; Basuli shows Tarzan a mysterious cave shaped like a skull head.
Synopsis (Part 2)
Tarzan and Basuli, upon further exploration, discover that the cave leads to a mine with men digging for gold under the direction of a greedy man named Ian McTeague, who is simply polluting the jungle river for his own self-centered gains. When Keewazi tells Jane and Professor Porter of what he knows of the mine, they inform him that due to the chemical separation of dirt from ores, the chemicals are being dumped into the river. Tarzan and Basuli infiltrate the mine, but are captured by McTeague. With some help from latecomers Terk and Tantor, Jane and Professor Porter rescue the pair, who have become friends through their trials together. Jane then proposes they build a dam, to cut off the water flow. When McTeague sees this and demands to have the water back, Keewazi refuses and collapses the dam, creating a flashflood that destroys the mine. This defeats McTeague and his men and sends them running away, leaving the jungle for good. After this, Tarzan, Jane, the Professor, Terk, and Tantor make peace with the Waziris as they take one of their canoes down the river to head for home.
- Part 2 of this episode was released during the September 11 attacks.