As part of the Mantle plan, a pollution-free city is constructed in the desert. Nambu and the Science Ninja Team have come into the city for the inauguration. In the middle of the parade, a man who introduces himself as the archaeologist Dr. Mukashiski is distributing leaflets for a dinosaur exhibition.

That night, the city is attacked by dinosaurs, and Ken sneaks into the dinosaur exhibition from Dr. Mukashiski. It turns out to be a jungle from the dinosaur period. Ken is caught by ivy made of metal and can escape into a subterranean sewer, but his bracelet is taken away this time. The Doctor takes the bracelet and, in order to make this is own merit, hides it.

Ken is severely scolded by Nambu who then orders the Science Ninja Team to get the bracelet back by all means. Nambu also leaves the attack on the dinosaurs to Red Impulse. Ken sneaks back into the sewer from which he escaped, and is discovered by the enemy, but G-4 followed him and saves him. Together they sneak into the base and rescue the three other team members who have been caught inside the base. They also recover the bracelet from Dr. Mukashiski. With the remote control destroyed by the Science Ninja Team, the magnetic propulsion energy of the dinosaurs explodes and they are destroyed along with the base.