In the Peruvian jungle, a Chopec Sentinel named Incacha is enraged by the pollution of his land by a contaminated oil well and the murder of one of his tribesman by an employee of the Cyclops Oil Co. In Cascade, Ellison examines the poison dart that killed the VP of security for the Cyclops Oil Co. and recognizes the markings of the Chopec tribe — the people who helped him develop his Sentinel powers.