治安が悪化した6号車から5号車への移住希望者が現れはじめる中、優斗（赤楚衛二）たちは、2026年に地球を激変させた大災害の経緯が書かれた航海日誌と、佳代子（松雪泰子）らが持ち帰ってきた光る不思議な石に、元の時代に戻るヒントがないかと思案していた。そんな矢先、玲奈（古川琴音）と明石（宮崎秋人）が、温水が出る川辺を見つける。しかしそこは6号車が領土を主張する場所で、5号車の面々は立ち入ることができない。そこで優斗と紗枝（上白石萌歌）が6号車へ交渉に向かおうとするが、紗枝の優斗への気持ちを知る直哉（山田裕貴）が2人を遮り、交渉役を買って出る。さらに、元の時代に戻れると信じていない直哉は6号車に移住すると言い出して･･･。
Rena et Akashi dénichent une source d'approvisionnement en poisson et de sel mais les passagers du wagon n°6 se la sont déjà appropriée. Kayashima part négocier.
As people who wish to move from Car No. 6 to Car No. 5, where the security situation has deteriorated, begin to appear, Yuto (Eiji Akaso) and his friends find a logbook that describes the circumstances of the catastrophe that drastically changed the Earth in 2026, and Kayoko ( Yasuko Matsuyuki and others have been wondering if there is a hint to return to the original era in the mysterious glowing stone brought back. Just then, Rena (Kotone Furukawa) and Akashi (Akito Miyazaki) find a riverside spot with warm water. However, this is a place where Car No. 6 claims territory and the members of Car No. 5 are not allowed to enter. Yuto and Sae (Moka Kamishiraishi) then head to Car 6 to negotiate, but Naoya (Yamada Yuki), who knows Sae's feelings for Yuto, interrupts them and offers to be the negotiator. Furthermore, Naoya, who does not believe that he can return to his previous era, says that he will move to car No. 6...
