Naoya (Yamada Yuki) and his friends learn that they have been transported along with the train 30 years into the future, and at the suggestion of Sae (Kamishiraishi Moka), each of them donates their belongings to survive the extreme situation together. to redistribute it equally. However, just as Yuto (Eiji Akaso) begins to gather food and water, he finds evidence that someone has taken a cart containing a large amount of drinks. Kayoko (Yasuko Matsuyuki) becomes suspicious as to who the culprit is, Rena (Kotone Furukawa) and Yonezawa (Joichiro Fujiwara) clash over the remaining mobile battery, and Naoya and Yu set out to find a water source in the sea of trees. To and Kato (Inowaki Kai) who tries to create water from plants... While everyone is desperately struggling to survive, one person unexpectedly begins to act out of control.