7x4 - Walker, Texas Ranger

After a young girl dies and other children fall seriously ill, Walker goes to the Cherokee reservation to investigate a factory that may be illegally dumping toxic chemicals into the reservation's water supply. When the Environmental Protection Agency tests the local waters and finds ""absolutely no trace of any toxins,"" Walker's suspicions lead him to dig deeper to uncover the real truth behind the factory. Although Walker and the Chief of Reservation Police, Sam Coyote (Eloy Casados), try to persuade the enraged Cherokees to wait for real proof, they insist on taking matters into their own hands and launch an all-out warrior battle to destroy the factory and its supervisors. (Taken from CBS Homepage)