The player takes on the role of a young boy who one day finds himself in an unexpected situation. A stranger hands him an old, shabby suitcase at a deserted train station with only one task: to deliver it to his destination at the end of a long train journey. But there's one catch - under no circumstances is he allowed to look inside.
The boy soon discovers that the suitcase is no ordinary suitcase. Everyone who looks inside it sees something different, and this thing dramatically changes the world around him. Sometimes it can be something banal, like a lost toy from childhood, that takes all the passengers back to their younger years. At other times, the contents of a suitcase can bring something dark and sinister into the world of the train, turning it into a nightmare. In some cases, what they see changes the boy himself - his mind, his memories, or even his physical form.
The game is divided into chapters, each representing a different train car or station where the boy must solve puzzles, escape danger, and interact with strange characters. Every decision, including whether or not to look in the briefcase, has an impact on the course of the game and its ending.
The boy gradually uncovers the secret of the briefcase and its connection to the mysterious man who entrusted it to him. The story leads him to question whether he can really trust his task and whether he should even deliver the briefcase to its destination. In the end, the boy must decide whether to resist the temptation to find out what the briefcase really holds, or to give in to his curiosity, even though it may have irreversible consequences for him and the world.