It has been several months since the murder case that shook Ponyville. Things have gradually returned to normal, and the events of those long months were placed into the backs of the townsponies' minds. For Twilight and her friends, the change was much more gradual, given their role in the case and the power they possessed, but it still eventually came to pass.

However, a call to arms is raised as a cave in the northern lands is suddenly shifted and warped, turning into a massive dungeon. Princess Celestia asks Twilight to assist a group of Persona-users in exploring the cave. Twilight and her friends balance the investigation of this enormous dungeon and maintaining friendly ties with the other exploration team members as they try to discover what has caused the cave's transformation…and the reason that hundreds of Shadows have made it their home.

Random tag is used because Slice of Life and Adventure conflict with each other.