The Game to Extinction (滅亡への遊戯 Metsubō e no yūgi) is the twenty-fourth and penultimate episode of Ultraman Z.
Juggler has finally revealed his true form to Haruki. Meanwhile, Celebro puts his final plan into motion. With their respective objectives out in the open, the situation takes a turn for the worse! As the shadow of despair creeps closer, their final enemy appears as a nightmare given shape!
Immediately after the conclusion of Ultroid Zero's first battle, Ultraman Z has seemingly rescued Yoko Nakashima. Yet, before his very eyes, she disappears and is replaced by Jugglus Juggler, who had disguised himself as the pilot! As the Majin states to a surprised Haruki that he "shouldn't just rely on [his] eyes", and prepares to climb aboard Ultroid Zero, Five King suddenly ambushes the area! Exclaiming that the fight wasn't going to be as easy now that Five King had arrived, Juggler transformed into Zeppandon.
Juggler addresses Five King's controller, Director Kuriyama, and says that he knows the human is being controlled by Celebro. Enraged, the alien parasite exclaims that he's finally learned Juggler's plan; to steal the final weapon the humans had built for him! Z manages to retrieve Yoko from Ultroid Zero's cockpit, and sets her down, before re-entering the fight. Z knocks down Five King, then Haruki asks Juggler what his true intentions are. Juggler replies by recounting a time when he cut down a great tree to stop a war, only for his efforts to be spurned. This is why he intends to steal Ultroid Zero, to show those who "think their justice is absolute" the error of their ways.
As the battle between Five King and Zeppandon continues, Ultraman Z tries his best to defeat Five King, but his energy was so low that he was quickly knocked to the ground, reverting back to Haruki just before his time ran out. Believing that he had a chance to steal Ultroid Zero for himself, Juggler had Zeppandon prepare to grab the downed machine, but Celebro retallisted by using Five King to begin to absorb Haruki’s unconscious body into the monster, and gave the Majin an ultimatum. Either he surrender the machine, or he’ll kill the alien’s human friend. After some hesitation, Juggler elects to stop Five King instead, and the two monsters fire their beams at each other, simultaneously knocking the duo out and reverting them back to their human forms. As Juggler lies injured on the ground, Kuriyama takes Haruki’s Belial Medal before leaving the scene, but not before Haruki noticed his eye glowing red, exposing the truth about the alien controlling him.
Haruki awoke at a nearby hospital, and found that Kojiro Inaba and Yuka Ohta were watching over him. Immediately asking as to the status of Yoko, Haruki learns from Yuka that as her injuries were only minor, Yoko is already ready for the next mission with Ultroid Zero. According to Kojiro, GAF has managed to figure out how to reduce the recoil from the D4 Ray to make it even safer, and Ultroid Zero has had the necessary repairs made to use the weapon again, though Yuka laments that Ultroid Zero is 'over-technology', and could have the capacity to destroy the Earth itself, theorising that the reason why so many monsters appeared to attack Zero was because they were acting on the will of the Planet, but the Director refuses to listen to her concerns. Haruki comes to the realisation that something is horribly wrong, and, remembering what he saw at the conclusion of the battle between Five King and Zeppandon, asks where Yoko is. Upon learning that she is likely to be at STORAGE HQ with the director, he panics, and tells the others of what he has seen, despite his injuries. Kojiro decides that Haruki needs to go for a drive with him so he can discuss the matters in more detail, and the duo leave the hospital with the STEGG.
Back at STORAGE HQ, Kuriyama replays footage of Hebikura transforming into Jugglus Juggler, and instructs Mai Yuki to be suspicious of anyone from the old STORAGE team, as they could be aliens as well, and that the use of weapons is authorised against them. He then goes to the hangar, where Yoko is observing the inactive Ultroid Zero. While at first, Celebro keeps up his facade, he soon drops it entirely, giving away the motivation for his final plan:
"At last. I've enjoyed many planets so far, but this moment always excites me. It's a wonderful spectacle. To see fools destroyed by a weapon of their own making, and to hear their cries of agony! I implant fear into planets with civilizations. They make weapon after weapon to defend themselves, and finally, with a weapon they created, they destroy their own civilization. I have a name for it - The Civilization Self-Destruction Game!"
Shocked at these words, Yoko has barely any time to react before Celebro emerges from Kuriyama's body and attacks her, selecting the human as his third host. With Kuriyama now unconscious on the floor, Celebro 'pilots' Yoko's body into stealing the Belial Medal, before throwing it towards Ultroid Zero, powering the machine up.
Mai and a team of GAF employees are caught by surprise by a tremor originating from the hangar room; Ultroid Zero is now fully activated, and tearing its way out of the facility! Now on the roof of the building, the Robot Ultra takes to the air, and Celebro initiates the final stage of his Civilisation Self-Destruction Game!
Meanwhile, Haruki receives a call from Yuka, who informs him of everything that has happened. Yoko is unresponsive to radio transmissions sent to the machine, and Ultroid Zero is refusing to accept the shutdown signal. To make matters even worse, Ultroid Zero is now attacking containment sites all over Japan, destroying the monsters within, and there is nothing GAF can do to stop it! The 36th Monster Surveillance Group in the city of Murobetsu, Hokkaido, mount a desperate counterattack as Ultroid Zero bears down on Crescent's containment facility, but are powerless to stop the machine from assaulting the monster's location, resulting in numerous fatalities, including Crescent himself, whose groans of agony were the last heard from the Minus Energy Monster before its energy and genetic material were harvested and absorbed, leaving absolutely nothing behind.
Ultroid Zero proceeds to travel across the Earth, dispatching five more monsters and absorbing their energy and DNA: Dancan, Arstron, Birdon, Satan Beetle and Majaba, before returning to Japan to attack the surviving mother Red King and her egg at Fukuma. After learning of these events from Yuka, Haruki urged Kojiro to stop the car, though he couldn't find a reason to explain why he needed to go when Kojiro asked him where he was going. His silence told his teammate everything, and, realising Haruki was Z's host, Kojiro encouraged him to depart.
Though Red King attempted to protect her unborn child from Ultroid Zero, she was powerless to stop the machine from attacking her. The robot stabbed straight through her armoured skin with its hand and absorbed everything it could, until nothing was left of Red King - the strong monster had been completely atomised and absorbed by Ultroid Zero. Celebro then set his sights on the egg itself, but Ultraman Z, who had arrived only a moment too late to save Red King, furiously entered the fight, fighting the robot away before grabbing hold of the egg to protect it. Through Yoko, Celebro gloated that Z had been a fine pawn in his scheme, and that humanity had given him "such a wonderful weapon", before activating all the Kaiju Medals he had to hand.
In an instant, Ultroid Zero's body began to transform, and parts of the monsters it had absorbed emerged where metal had once been. As Celebro introduced the new creation as "The King of Death and Destruction", Ultroid Zero's body was almost completely destroyed, revealing a brand new Chimera Kaiju - Destrudos, the Annihilation Armor Monster!
As Z fought hard to block Destrudos's attacks and protect the egg, Yuka analysed the new monster, and despaired that she couldn't find the location of Ultroid Zero's cockpit in the combination's body. A team of GAF soldiers entered the room, and asked Yuka to submit to questioning; Kuriyama had been found unconscious in the hangar room, and had yet to wake up. As Yuka began to realise what had happened, the soldiers were suddenly knocked out by an unseen person.
Z had just enough time to put the egg into a gap between the rocks, before facing Destrudos directly, but it quickly became clear just how outmatched he was. With Destrudos easily manhandling Z, the Ultra switches to his Beta Smash form, but most of his strong punches and kicks simply rebounded off Destrudos's surface, and the beast delivered a wicked clothesline that floored him! Switching again to Gamma Future, Z attempted to have his Gamma Illusion make its mark on the monster, to little success, and an attempted Zestium Drive backfired when Destrudos simply blocked the attack, then sent it back to its source.
Badly injured, Z's Color Timer began to blink, allowing Destrudos to get in close range and lift the Ultra off the ground. Celebro began to revel in what was taking place; for now, everything was going according to plan. The possessed Yoko pulled the trigger for Ultroid Zero's D4 Ray, now repurposed into the even stronger Destrudo D4 Ray! With Z unable to escape Destrudos's vice-like grip, Haruki looked on in horror, but Z managed to muster the energy to break free, instantly preparing his full-power Zestium Beam in an attempt to seal the D4 Ray's beam, like he had done to the rift that followed the original weapon's second use. Though Z's beam briefly locked with that of the Destrudo D4 Ray, it was all in vain; vastly outranked by the power of the Destrudo D4 Ray, Z's attempts at defending were futile, and the beam impacted his body, instantly defeating him. Critically injured, Z vanished in a burst of light.
In a red void, Haruki lay unconscious, yet his consciousness remained active, having been awoken by Z in his original form, his Timer still blinking red. There, Z announced that it seemed as if their team-up was to end. When Haruki asked Z to explain further, he explained that both his body and that of Haruki had sustained critical damage as a result of the Destrudo D4 Ray - if the human were to attempt another transformation, both he and the Ultra would surely die. After apologising for dragging Haruki into all this, Z vanished, his heart filled with sorrow. As he left, Haruki cried out for him, but it was already too late.
Haruki awoke in a store room somewhere in the HQ, full of emblems and banners from STORAGE's tenure at the facility. He had little time to gain his bearings before Hebikura emerged, flanked by the rest of the team, and were clad in the uniform of STORAGE. It seemed as if GAF had decided to reactivate the group! Yuka announced that over the past few days, Destrudos had embarked on a worldwide rampage, destroying numerous cities. GAF were in the process of attempting a counterattack, but their efforts were so far in vain, and elements of the organisation were being eliminated one after the other. When Haruki asked what they were going to do next, Hebikura replied "isn't it obvious?" and presented Haruki with his uniform, officially readmitting him to the team, and concluding by saying "We're getting our old base back."
Ultraman Z and Ultraman Zero Voice Drama
It Starts Here (ここから始まる Koko Kara Hajimaru)
Z fights Zero in the test, but fails. Not giving up, Z continues to fight even after being beaten, but is knocked out. When Z recovers, Zero tells him that Zoffy decided that Z could join the Inter Galactic Defense Force because of his efforts, but Z still had a long way to go before Zero would call Z his disciple.
- Haruki Natsukawa (ナツカワ ハルキ Natsukawa Haruki): Koshu Hirano (平野 宏周 Hirano Kōshū)
- Yoko Nakashima (ナカシマ ヨウコ Nakashima Yōko): Rima Matsuda (松田リマ Matsuda Rima)
- Yuka Ohta (オオタ ユカ Ōta Yuka): Hikari Kuroki (黒木ひかり Kuroki Hikari)
- Shota Hebikura (ヘビクラ ショウタ Hebikura Shōta): Takaya Aoyagi (青柳 尊哉 Aoyagi Takaya)
- Kojiro Inaba (イナバ ルリ Inaba Kojirō): Jun Hashizume (橋爪 淳 Hashizume Jun)
- Director Kuriyama (クリヤマ長官 Kuriyama Chokan): Hisahiro Ogura (小倉 久寛 Ogura Hisahiro)
- Satoshi (サトシSatō Reo) ): Reo Satou (佐藤 玲央
- Seiji (セイジTsunoda Fūma) ): Fuuma Tsunoda (角田 楓馬
- Hiroshi (ヒロシTakaoka Daichi) ): Daichi Takaoka (高岡 大地
- Mai Yuki (ユウキマイ Yūki Mai): Maya Hayashi (林 摩耶 Hayashi Maya)
- Guard by Room:
- Ultraman Z (ウルトラマンゼット Urutoraman Zetto): Tasuku Hatanaka (畠中 祐 Hatanaka Tasuku)
- Beliarok (ベリアロク Beriaroku): Yuki Ono (小野 友樹 Ono Yūki)
- Ultraman Z: Hideyoshi Iwata (岩田 栄慶 Iwata Hideyoshi)
- Ultroid Zero: Shinnosuke Ishikawa (石川 真之介 Ishikawa Shinnosuke)
- Destrudos: Yoshiki Kuwahara (桑原 義樹 Kuwahara Yoshiki)
- Five King: Satoru Okabe (岡部 暁 Okabe Satoru)
- Zeppandon: Hiroyuki Arai (新井 宏幸 Arai Hiroyuki)
- Red King B: Kenji Kajikawa (梶川 賢司 Kajikawa Kenji)
- Ultraman Z
- Alpha Edge
- Beta Smash
- Gamma Future
- Delta Rise Claw
- Jugglus Juggler
- Five King
- Ultroid Zero
- Red King B
- Grigio Raiden (Flashback)
- While ranting about Director Kuriyama being ignorant of her warnings, Yuka stated that the monsters act under the will of Earth to destroy Ultroid Zero, which was considered as an abomination to the planet. Her theory of Earth as a living being and how life on Earth interact with their surroundings are based on the Gaia hypothesis by James Lovelock, in which the Earth and its organisms can be seen as a single collective organism.
- The name of the fictional city where Crescent is contained, Murobetsu, is a portmanteau of director Kiyotaka Taguchi's hometown of Muroran and the neighbouring city of Noboribetsu, both being cities in Hokkaido's south.
- The scene where Z parts with Haruki is a throwback to Ultraman's conversation with Zoffy in the final episode of Ultraman.