The college student Stacey comes to a small train station to travel home for Thanksgiving, and notes a different train schedule. She buys a two-way ticket and embarks on the last car of the train. She notes that there are only three passengers in the car despite the others cars being crowded. The passengers are an old lady named Mrs. Crane, an old man and a restless boy, and they are all afraid of the tunnels. Stacey decides to move to another car and finds that the communicating door is closed. When the conductor arrives, he returns an one-way ticket to Stacey and does not allow her to move to another car. What is happening in the last car?
—Claudio Carvalho, Rio de Janeiro, Brazil