Zetton's Daughter (ゼットンの娘 Zetton no Musume) is the thirteenth episode of Ultraman Max.
Invaders approach Earth, while the unknowing UDF places new satellites in orbit. A woman walks up to the barricade in front of the entrance to Base Titan. She says she wants to see Professor Yukari Yoshinaga, and says that she is Zetton's daughter. Both the professor and chief Kenzo Tomioka are perturbed by this, but the professor recognizes the girl.
The two woman meet, and the other is revealed to be Natsumi Oda. She says Max will be killed, by a Zetton, and she was told so by her father, a Zettonian, and that she came as a warning. She used to be a psychic girl, but it seemed to wear off.
Later, DASH prepares for attack: the Zetton is coming. The alien sends a message: "Tell Max to prepare to die."
Kaito and Mizuki investigate the location the signal came from. On the way there, they see Natsumi get hit by a truck. Despite the injuries, she seemed well the next day. The two investigate her personal life. They learn that her mother passed away when she was about 14, and that she helps elderly in the neighborhood.
That night, Natsumi wakes up to the Zettonian. He tells her she has Zetton nano-DNA inside of her. It then takes over. She infiltrates Base Titan and attacks Elly, but is confronted by the team. She attacks them with a lightsaber and flees, summoning the Zetton monster, flying off after defeating Koba and Sean. Three surveillance satellites are destroyed as the kaiju comes towards earth.
Kaito and Mizuki find Natsumi unaware of the proceedings, when Zetton appears. Kaito runs off and transforms as the monster rampages. DASH also deploys, but the kaiju shrugs off their attacks with the Zetton Shutter. With Max's Color Timer blinking He uses his Max Cannon to destroy him but Zetton uses the Zetton Shutter. Just as Max was about to break the Zetton Shutter he collapsed as a result of using up all his energy. He is on the point of killing Max when a strange Ultra arrives, Ultraman Xenon.
Xenon is also no match for Zetton, but summons the Max Galaxy for the titular Ultra. Using its power, he destroys the monster. Xenon warns Max that four space fighters infiltrated Earth and leaves. Back at DASH Elly has Footage from the destroyed satellites revealing four space fighters. The episode ends with Natsumi staring up to space.
- Kaito Touma (トウマ・カイト Tōma Kaito): Sōta Aoyama (青山 草太 Aoyama Sōta)
- Shigeru Hijikata (ヒジカタ・シゲル Hijikata Shigeru): Kai Shishido (宍戸 開 Shishido Kai)
- Mizuki Koishikawa (コイシカワ・ミズキ Koishikawa Mizuki): Hitomi Hasebe (長谷部 瞳 Hasebe Hitomi)
- Kenjiro Koba (コバ・ケンジロウ Koba Kenjirō): Nobuyuki Ogawa (小川 信行 Ogawa Nobuyuki)
- Sean White (ショーン・ホワイト Shōn Howaito): Sean Nichols (ショーン・ニコルス Shōn Nikorusu)
- Elly (エリー Erī): Hikari Mitsushima (満島 ひかり Mitsushima Hikari)
- Kenzo Tomioka (トミオカ・ケンゾウ Tomioka Kenzō): Susumu Kurobe (黒部 進 Kurobe Susumu)
- Yukari Yoshinaga (ヨシナガ・ユカリ Yoshinaga Yukari): Hiroko Sakurai (桜井 浩子 Sakurai Hiroko)
- Natsumi Oda (龍谷修武 Oda Natsumi): Nao Nagasawa (長澤 奈央 Nagasawa Nao)
- Ultraman Max (voice) (ウルトラマンマックス（声） Urutoraman Makkusu (koe)): Kazuya Nakai (中井 和哉 Nakai Kazuya)
- Ultraman Xenon (ウルトラマンゼノン Urutoraman Zenon): Osamu Ryukoku (龍谷修武 Ryukoku Osamu)
- Narration (ナレーション Narēshon): Shiro Sano (佐野 史郎 Sano Shirō)
- Ultraman Max Volume 4 features episodes 11-14.
- Ultraman Max Complete Season.
- Zoffy was originally going to appear in this episode, but was replaced with Xenon.
- This is Zetton's first actual appearance since Return of Ultraman (Zetton II) as himself (not counting Powered Zetton from Ultraman: The Ultimate Hero).
- This is also Alien Zetton's first appearance since the original Ultraman.
- The episode was premiered on American television by TOKU on March 7, 2017.