One year ago, Guy and Leo are standing in front of the prone Galeon. Guy tells his father that he understands his responsibility to help all of mankind. In the present, Mikoto wakes up to see the explosion engulf GaoGaiGar and screams out for Guy. The explosion becomes a stable Grand Nova with Guy still trapped inside it. Medical staff see to the unconscious Space Development Corporation workers as Sakura wakes up and sees the Grand Nova outside. 3G analyzes the Grand Nova, and Leo explains that it was formed by the fake Zonder core performing nuclear fusion using Hell and Heaven as a catalyst, resulting in a miniature sun. Swan reports multiple explosions occurring inside the Grand Nova. Pasdar congratulates Pizza on a job well done, and Pizza tells them that they can now move on to the next phase. Penchinon praises Pizza but warns him not to forget about Mamoru. Next to them is the real core of EI-18. Swan locates GaoGaiGar near the center of the Grand Nova but can’t reach Guy. The Amphibious Armored Maintenance Vehicle approaches the edge of the Grand Nova and Hyuuma reports that the repairs on the 3G robots are complete. Taiga orders the use of the Eraser Head but Leo reminds him that they still can’t defeat the Zonder without Hell and Heaven. Taiga says that when that time comes he’ll approve the use of the G-Tool. HyoRyu and EnRyu combine and Swan notices that Mamoru is missing. ChoRyuJin fires an Eraser Head at the Grand Nova, which shrinks briefly before expanding again. Leo says that they can only try to keep dispersing it, so Taiga orders another Eraser Head to be fired. Mamoru runs towards the Grand Nova, blaming himself for Guy’s fate. Volfogg stops him and says it’s too dangerous. Mamoru retorts that he can sense the Zonder under the Grand Nova and that Guy will die if they keep wasting time. Volfogg consents under the condition that he escorts Mamoru and pulls out a heat resistant suit for him. Swan detects an unknown cavity inside the Grand Nova while ChoRyuJin continues to fire Eraser Heads. Mikoto watches the Grand Nova and thinks Guy is dead because of her. Polonaise and Primada watch with glee as ChoRyuJin struggles under the stress of firing multiple Eraser Heads. Entouji detects ZO particles in the center of the Grand Nova, and 3G finally realizes that it’s a Zonder metal plant.
Guy wakes up and realizes he’s inside the Grand Nova, with Galeon barely keeping them intact with a constant Protect Shade. Mamoru and Volfogg infiltrate the sewers where Mamoru senses the core to be. Volfogg detects a barrier and penetrates it with his Melting Siren. Penchinon detects the intrusion and surmises that it must be Volfogg. Guy tells Galeon they’re nearly out of energy and asks for one last burst. A battered ChoRyuJin fires his tenth Eraser Head despite Hyuuma’s protest and Guy activates his Hyper Mode, managing to escape the Grand Nova at last. A recovered Mikoto walks back into the main order room and resumes her duties. Penchinon fires explosive drones at Volfogg and the latter activates his holograms. The holograms pelt the two Machine Kings with a barrage of projectiles and Pizza disperses the illusions. With GaoGaiGar and ChoRyuJin repaired, Guy asks Taiga to let him use Hell and Heaven, but Taiga says even that won’t defeat the Grand Nova. With no choice left, Taiga finally authorizes the use of the G-Tool, a large mallet. Volfogg summons the Gun machines and combines into Big Volfogg, then uses his Daikaiten Madan attack to destroy Penchinon’s drones. The Pliers deliver the G-Tool, aka the Goldion Hammer, to GaoGaiGar, while Taiga and Mikoto unlock its safety device from their consoles. Big Volfogg gains the upper hand on the Machine Kings, but Pizza realizes he’s just a distraction to allow Mamoru to approach the Zonder core. Pizza dashes towards Mamoru heedless of Penchinon’s warning. Guy completely disintegrates the Grand Nova, along with EI-18 and the metal plant, with the Goldion Hammer. Pizza is repelled and injured by Mamoru’s barrier and Penchinon tells him that they’ve lost the Zonder metal plant, so they both retreat. Big Volfogg asks Mamoru if he’s alright, and Mamoru says that he can’t sense the Machine Kings like he does normal Zonders. The Goldion Hammer causes a hole in the ground and ChoRyuJin catches the nearly wrecked GaoGaiGar before it falls in. Mamoru finally purifies the core. Leo says they need to improve the Goldion Hammer and Mikoto is happy that Guy survived. Mamoru runs to his recovered father in the infirmary.
First a screwdriver, then pliers, and now a giant hammer complements GaoGaiGar’s arsenal of tools. And this one packs quite a wallop both to the receiver and user, what with leaving GaoGaiGar a smoking wreck after use. Though if it does so much damage, what makes it less dangerous to Guy than Hell and Heaven? Pizza and Penchinon seem to have forgotten about targeting Mamoru in favor of a double whammy of baiting Guy to his own death and growing a Zonder metal plant right under his nose. It’s also nice to see Mamoru continue to take action and not just be the one trick pony character who’s only there to purify the cores after a battle. Something that I haven’t got around to bringing up before is how very well organized 3G is. As Ben Davis mentioned in his now defunct Mecha Musings column, 3G has a damn good security system. Everything has to go through Taiga, Final Fusion won’t happen if Mikoto doesn’t slam that glass panel, and the Goldion Hammer needs two keys on two different people before Guy can use it to ruin a Zonder’s day.