It's Nightmare Night once again, and Diamond Tiara is feeling mischievous. She remembers an old story about this abandoned train station that was closed down due to a massive accident long ago.
She finds the mysterious station and the tunnel leading up to it, and persuades the Cutie Mark Crusaders to join her on her journey into the pony-made cavern.
This story was inspired by the urban legend simply known as the Silverpilen Ghost Train. It supposedly haunts the Metro stations of Stockholm, Sweden, appearing late at night. A very interesting tale, if I do say so myself.
The cover art in particular is a picture of the abandoned Kymlinge station. The station is linked to the legendary train's story as being where the passengers of Silverpilen "get off".