Cobra seizes control of a new satellite for use with a new transportation device, and Duke is captured in the attempt. The G.I. Joe team learns that they must build their own device to defeat Cobra.

The Joes travel to the arctic to retrieve rare minerals to fuel their MASS device, but Cobra ambushes them, and Snake Eyes is presumed dead. Duke manages to escape the Cobra base with the help of a slave girl, but he is injured and cannot remember the base's location.

Duke recovers from his injuries; Snake Eyes wanders the attic, poisoned by the radioactive crystal elements he recovered from a Cobra trap.

G.I. Joe tries to throw off Cobra with a false surrender while mounting a mission to the Ring of Fire for the third element. Destro sabotages the operation but is pursued by Scarlett.

Part 5 of 5. Destro returns to Cobra Mountain with Scarlett as his prisoner. As he takes control of the operation from Cobra Commander, the stakes are raised for the Joe team to stop them once and for all with an all-out assault on Cobra Mountain!

A Cobra attack on a Joe convoy results in the capture of Duke and Snake Eyes and the theft of a laser core which Destro uses to power his new weapon, the Weather Dominator. Meanwhile, Cobra Commander is briefly captured but rescued by Zartan.