"Friendship is an island that you retreat to. And you fall on the floor and laugh at all the ninnies who don't have enough brains to have your good taste." --Ray Bradbury
Rockhoof has returned to Equestria after a thousand years in Limbo. He's also severely depressed. Princess Luna pays him a visit in his lonely dream to find out what troubles him.
Preparations halt when Princess Celestia forbids the playing of the Equestrian national anthem at a concert after a copy of its original is discovered to still exist. Despite her warnings, Octavia Melody endeavors to uncover the truth.
Nightmares have been plaguing you for the last three months. Each one has ended the same way, with you going to sleep in the orphanage you lived in back on earth, and waking up back in the Castle you now called home.
Mister Lonely Heart is a self-styled "Grievance Counselor", a changeling who mimics ponies that his clients have issues with. When Twilight Sparkle pays him a visit, he finds out how painfully neurotic the Princess of Friendship really is.
Everypony thinks that Queen Chrysalis escaped capture, but Discord's captured her and holds her prisoner in his home dimension. She's going to get reformed by the Master of Mayhem. Eventually. Maybe. Theoretically.