GUTS to the Sky Part 2 (GUTSよ宙（そら）へ 後編 Gattsu yo Sora e (Kōhen) is the 20th episode of Ultraman Tiga.
As seen in the previous episode, the Artdessei is being menaced by a large island-like ship, and Ultraman Tiga was being held by a robot which was about to self-destruct. With the lights in the robot's head blinking off one by one, Tiga manages to kick off one of the robot's legs, freeing himself. The robot still tries to hop to the base, blasting Tiga away with its jet pack, but Tiga manages to grab it and fly with it into the sky. Tiga's Color Timer stops blinking and he disappears, as the robot's final light flashes, culminating in its destruction.
The GUTS officers in the Artdessei witness the explosion, and wonder about Tiga's condition, when they spot a big wave of robots flying towards them. They start attacking the ship, with Shinjou and Horii going out in GUTSwings. Meanwhile, a search is started for Daigo, who was last spotted fighting the robots in the hanger, and he is found floating in the ocean.
Shinjou and Horii are attacking the robots, trying to keep them from flying into the Artdessei. The island keeps sending out more and more robots to stymie them. Daigo is still floating in the ocean, and finds himself in a white landscape, with Yuzare's and then the Kyeloid's words echoing at him. He questions why he has to be Tiga and fight alone, that he's already lost, when the 'sky' above him shatters to show the battle in space. Shinjou and Horii are having trouble contending with the robots when Rena tells them to return to the ship as the Maxima-Overdrive has finished charging.
Yuzare appears to Daigo, and tells him he's not the only one who can become Tiga, nor is he the only one fighting. If humans don't work together, she explains, they will vanish much like her civilization did. Yazumi's call snaps him out of the white landscape, and he wakes up as Yazumi speeds towards him in a boat. They haul a piece of the robot onto the boat, so it can be examined.
Rena starts the Maxima-Overdrive, as the island creeps closer to them. Rena's controls stop working as a door opens on the island, and it starts drawing in the Artdessei. Daigo returns to the base as the Artdessei loses contact. Professor Yao theorizes that the robots only started being a problem when the Maxima-Overdrive was started, and talks to Yazumi who is looking over the metal piece. He manages to get it communicative, as it states that it was left over to make sure humans never reached forbidden technology like the Maxima-Overdrive. Yao is angered that he spent 20 years coming up with the idea, but Daigo tells him it was something that was supposed to happen anyway. Yazumi and Yao figure out that if the robots are thriving on the Maxima-Overdrive system, they can hit it with negative waves to stop the robots. In other words, run the system in reverse, so Daigo volunteers to take the practice craft to the island.
Daigo lands on the surface of the island, and manages to contact the Artdessei by blowing a hole into the island and dropping a probe onto the Artdessei. They coordinate the procedure to offset the waves of regular and negative Overdrive particles, with the door opening for the Artdessei. However, this causes a giant robot to start accumulating on the surface. Daigo transforms into Tiga to battle this robot as the Artdessei escapes from the island.
As before, Tiga's attacks don't affect the robot, and as the Artdessei flies away, Tiga tries to follow it. But then the robot shoots a lightning bolt at him, causing him to fall back to the island's surface. It keeps shocking him with the bolts, as his Color Timer starts blinking. When he stops moving, it starts sinking into the island. Tiga then gets up, and tries to fly away again, but the robot grabs onto his legs. Artdessei flies in to help him, using the Maxima-Overdrive energy to power the cannon and shoot the robot.
As the beam hits the robot, Tiga grabs Daigo's ship and hurls it towards the Artdessei, which prepares to retrieve it after they escape the island. Tiga sends his Zepellion Ray at the island, destroying it. Daigo then appears on the Artdessei to the relief of everyone. Yao is dismayed that his work wasn't original, but then Yazumi reminds him that humanity must always evolve, and they must make sure it doesn't go in the wrong direction.
- Daigo Madoka (マドカ・ダイゴ Madoka Daigo): Hiroshi Nagano (V6) (長野 博（Ｖ６） Nagano Hiroshi (Bui Shikkusu))
- Rena Yanase (ヤナセ・レナ Yanase Rena): Takami Yoshimoto (吉本 多香美 Yoshimoto Takami)
- Megumi Iruma (イルマ・メグミ Iruma Megumi): Mio Takaki (高樹 澪 Takaki Mio)
- Seiichi Munakata (ムナカタ・セイイチ Munakata Seiichi): Akitoshi Ohtaki (大滝 明利 Ōtaki Akitoshi)
- Masami Horii (ホリイ・マサミ Horii Masami): Yukio Masuda (増田 由紀夫 Masuda Yukio)
- Tetsuo Shinjoh (シンジョウ・テツオ Shinjō Tetsuo): Shigeki Kagemaru (影丸 茂樹 Kagemaru Shigeki)
- Jun Yazumi (ヤズミ・ジュン Yazumi Jyun): Yoichi Furuya (古屋 暢一 Furuya Yōichi)
- Ultraman Tiga (ウルトラマンティガの声 Urutoraman Tiga no Koe): Yuji Machi (真地 勇志 Machi Yuji) (voice)
- Ultraman Tiga Volume 5 Features Episodes 17-20.