Celestia realizes that Luna is very sad after Discord's petrification. Celestia, concerned for her sister, she is determined to discover the reason for Luna's sadness.
Princess Luna is trying to find ways to remember the important ponies from her past, but is finding that it is difficult to maintain a perfect recall over the events of a long life. Then Discord gives her something unexpected to think about.
While spending your first night in Equestria, a visitor comes into your mind to reassure your safety. And who knows? You and Luna may find more than a friend in this dream come true.