After Leader X is seemingly destroyed for good at the end of Gatchaman II, a fragment of him that survived grows and mutates into Z. With the head of the Egobossler family, Count Egobossler (and his two subordinates Mechandol and Kempler), Z is bent on destroying the Earth, and the Science Ninja Team, once more.<br><br> In the wake of Anderson's death, Dr.Nambu has become the new head of the ISO, while the team is now confined to the Gallatown (aka "G-Town") underwater base. Engineer Kamo is introduced, and after the New GodPhoenix is destroyed early on, the team receives the new Gatchaspartan as their mecha. The Gatchaspartan has a special mode as well, called Hypershoot, that can only be utilized by Ken (with his new "Gatchafencer" sword).<br><br> As the series progresses, it is learned that the radiation exposure from constant use of the Hypershoot is slowly killing Ken, and that continued use would mean death. Meanwhile, Z plans to destroy the earth with an antimatter asteroid, codenamed "Poison Apple".<br>