第 17 集: Chiko 陪同 Kouhei 前往秘密實驗室,而 Ken 則面對一位刀槍不入的少女。

Chiko goes with Kouhei, leaving a note on her bed for Tome that she will "definitely be back". Ken sees Chiko in the car and follows but is attacked by a girl who is very much like the boy who attacked Chiko last time. It doesn't seem she can be wounded as she is hit by a metal object of some sort on the road and has no injuries from it. Ken lights the girl on fire, destroying his motorcycle, yet to his surprise the girl has not a scratch and comes at him again. This time, Dr. Kayama intercepts it (the girl seems to be a more stable experiment much like Dr. Kayama herself). They escape. Meanwhile, Chiko and Kouhei have gone underground to a secret laboratory where Kouhei is trying to create the "Fourth Form of Water" which is light. Chiko has connected this research to the poem and refuses to help Kouhei. He shows her that he has Shunka captive and will use her in an experiment if she does not help him. So she give him what he wants, only to be deceived. Twenty Faces shows up and rescues Shunka before facing Kouhei. (Source: Wikipedia)
集數
- 第 13 集 · 白髮惡魔綁架奇可,引發飛艇對峙與拆彈行動
- 第 14 集 · Ken和Chiko駕駛飛船,Tome則確保監護權與住所。
- 第 15 集 · 冬馬招待春香,同時懷疑明音,而明音正遭到千子阿姨派出的刺客追殺。
- 第 16 集 · Chiko 拜訪秘密山丘,並遇見曾是 Twenty Faces 教師的 Kakashima Kouhei
- 第 17 集 · Chiko 陪同 Kouhei 前往秘密實驗室,而 Ken 則面對一位刀槍不入的少女。
- 第 18 集 · 二十面相與光平對峙,千子則營救被俘的春香。
- 第 19 集 · 千鶴子逃離設施後從東京出逃,肯趕來營救她。
- 第 20 集 · Chizuko 與盟友在塔樓前與 Kohei 及基因改造兒童對峙。
- 第 21 集 · Chizuko 和 Kohei 在塔上對峙,平民則撤離東京。