Burn! Terrible-Monster Hell (萌える 超獣地獄 Moeru Choūjū Jigokū) is the third episode of Ultraman Ace.
On patrol, Minami witnesses the sky crack open and a monster emerges. Destroying a bridge with a little boy on it, a passenger plane flies overhead and it, too, is destroyed. TAC investigates the wreckage and finds no sign of the little boy, nor the monster Minami described. Hokuto finds the yellow hat belonging to the boy which happens to have his name, Shiro Nakamori, printed on it. Hokuto locates his parents and upon meeting the boy, realizes something is wrong with him after he swipes his gun and attempts to kill him with it! It's discovered the boy has been possessed by the Yapool, using him as a host for the monster Vakishim. Luring the main TAC members away with a decoy, Vakishim is sent to destroy the TAC headquarters at the base of Mount Fuji.
- Seiji Hokuto (北斗 星司 Hokuto Seiji Hokuto Seiji): Keiji Takamine (高峰 圭二 Takamine Keiji)
- Dan Umezu (梅酢 ダン Umezu Dan): Umezu Akinori (梅酢秋則 Akinori Umezu)
- Yuko Minami (南夕 子 Minami Yūko): Mitsuko Hoshi (星光子 Hoshi Mitsuko)
- Goro Ryu (竜五 郎 Ryu Goro): Tetsurō Sagawa (瑳川哲朗 Sagawa Tetsurō)
- Ichiro Yamanaka (山中 一郎 Yamanaka Ichiro): Okita Shunichi (沖田 駿一 Shunichi Okita)
- Tsutomu Konno (今野 勉 Konno Tsutomu): Masaaki Yamamoto (山本正明 Yamamoto Masaaki)
- Noriko Mikawa (美川 のり子 Mikawa Noriko) Keiko Nishi (西恵子 Nishi Keiko)
- Kozo Yoshimura (吉村公三 Yoshimura Kozo): Koyo Sano (佐野光洋 Sano Koyo)
- Kaji Yoichi (梶 洋一 Yoichi Kaji): Katsumi Nakaiyama (中山 勝己 Nakaiyama Katsumi)
- Ultraman Ace (ウルトラマンエース Urutoraman Ēsu Voice): Gorō Naya (納谷悟朗 Naya Gorō)
- Yapool (ヤープル Yapurū Voice): Hirofumi Takada (高田 裕史 Takada Hirofumi)
- Narrator (ナレーター Nareta): Shin Kishida (岸田 森 Kishida Shin)
- Ultraman Ace Volume 1 features episodes 1-4.