On a seemingly infinite train traveling through a barren landscape; the cars of the train contain a variety of bizarre and fantastical environments. The passengers on the train are people it picks up who have unresolved emotional issues or trauma. As they travel through the train's cars, their adventures within give them the opportunity to confront and resolve their emotional problems, represented by a glowing number on their hand that goes down as they successfully confront these issues. Once they resolve their issues and their number reaches zero, a portal opens and they are able to leave the train and return home.

You suddenly appeared on the train after struggling with your parents’ recent divorce. You’re accompanied by a small, confused robot named "One-One", and Atticus, the ruler of a kingdom of talking corgis.