Gel Sadra builts a beam cannon in a secret base. Governor X sends the main component by subterranean rocket from his headquarters to Gel Sadra's base. But the rocket goes out of control when it collides with a crack in the Earth's crust and heads the surface... Gel Sadra is about to collect the main component and destroy the rocket in order to maintain the secret, but through an accident with the explosives, she is left all alone. Elsewhere, the Science Ninja Team has noticed the rocket through a satellite, and hurries towards the spot of the accident. The Science Ninja Team investigates the surroundings. Ken follows some mysterious footprints and unexpectedly runs into Gel Sadra. The transmitter is not working and Ken is forced to act alone. A fight ensues between Ken and Gel Sadra, where both depend only on their bare hands. Ken follows the fleeing Gel Sadra and, as a consequence, finally arrives at the enemy base. However, he is surrounded by the enemy. The other team members hurry there. They destroy the secret factory with the tornado fighter. While returning, Jinpei accidentally collects the main component that Gel Sadra possessed before. The day when the riddle of the main beam cannons will be solved is not far away anymore.