Kagaku ninja tai Gatchaman

Somebody sneaks into Galactor's Headquarters and a plan to build a huge base in San Frangeles is relayed to the Science Ninja Team. Ken and the others are baffled at the voice of the communication. It sounds exactly like Joe's. Elsewhere, Galactor has a corps of knights, clad in black armour made of a special Sigma lightray-strengthened steel, sneak in places to steal nuclear energy. The plan is to have them destroy the city of San Frangeles while the base is still being completed. The Black Knights are actually internationally wanted criminals. Since the Science Ninja Team has been told that the escapees have secretly built a town, they go to the ruins of the prison on Alamo Island by San Frangeles. Jinpei is given precise instructions by a voice that sounds like Joe's and the Ninja Team discovers an enemy base that is still being constructed on the bottom of the sea. They sneak into it and install a time bomb. However, they are captured by Gel Sadra. The Science Ninja Team dares to try the Tornado Fighter to escape. The base explodes and they end up floating on the sea, from where they are again rescued by a mysterious person.