Captain Dojima transforms into a strong bullet ant (Paraponera clavata) and kills the giant cockroach.

Ichiro transforms into a sleeping chironomid (Polypedilum vanderplanki) then vents air from the vessel to asphyxiate the cockroaches.

Osako transforms into a durable black weevil (Pachyrhynchus infernalis) while Mary becomes a rainbow stag beetle (Phalacrognathus muelleri) with optical camouflage capabilities.

It is revealed that Ko Honda, the mission director, is communicating with the roaches, who appear to have human intelligence.

As they prepare for battle, Shokichi Komachi transforms into a deadly Asian giant hornet while Jim Muto becomes a desert locust with powerful melee attacks and flying ability.

She revives Ichiro with water and they launch the BUGS 2 back toward Earth with a giant cockroach egg on board.

Surprised at the new evolutionary advantage of the giant cockroaches, Ko Honda commands the BUGS 2 to fall back to the surface of Mars.

Back on the surface they face the remaining members of the human expedition team, all of whom inject another dose of DNA to transform and do battle with the hordes of cockroaches.

Ko Honda admits that it would be their downfall and suggests preventing the vessel from returning to Earth and then disappearing from Japanese society.

She attempts to shoot him but he stops the bullet and tosses a spider at her which releases a toxic purple spray and kills her.