When Overkill gets hold of a top-secret biochip, he's able to integrate his synthetic biology with the power of the machine and build a powerful body to battle Sigma Six. Then he tries to steal the remaining chips and turn the world into an electronic extension of himself, and the unlikely pair of Hi-Tech and Spirit is sent to stop him.
While Scarlett, Stone and the others escape from the Cobra catacombs, Duke arrives at the main Cobra Coliseum to battle Cobra Commander. But first, he must fight Cobra's three best robotic assassins, beginning with Overlord Vortex.
Firefly, Tunnel Rat and Heavy Duty set out to find a Cobra defector and bring him back to Sigma Six. But after Duke almost kills himself testing Hi-Tech's new power suit, team members begin to disappear.
After Snake Eyes vanishes investigating a strange power source in the remote Demons Forest, Duke, Scarlett and Heavy Duty head out to rescue him. The forest is said to be haunted, but what's really haunting them is Cobra, who has been perfecting a deadly plasma device.
It's Tunnel Rat vs. Heavy Duty in a hamburger-eating contest, with the loser joining Snake Eyes and team to undergo grueling ninja training. Tunnel Rat loses and heads to a trap-filled ancient temple for the first test. Waiting for him there: Cobra.
Cobra Commander orders Destro to the Central Museum to obtain a dangerous top-secret nanotechnology, but Destro has a plan of his own. He wants to use the mission to test his new Cobra mind-ripping technology (which turns humans into slaves) on the Sigma Six team.
The Sigma team's on the trail of the stolen Dragon Hawk copter---and into a Cobra trap. Destro and Cobra Commander hope to download and crack Hi-Tech's secret Sigma system from the Dragon Hawk, then lure the Sea Titan within range of the Sigma island missile defenses.
Zartan and the Dreadnoks steal a top-secret plasma device for Cobra Commander, and when Duke and the Sigmas investigate, a strange battle copter attacks Zartan's battle cruiser while a mysterious agent stalks Duke, seemingly for fun.