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.
Twilight and Queen Novo apologize to one another over their respective actions when Twilight tried to steal the Pearl of Transformation in order to save Equestria from the Storm King.
When the ponies prepare a concert in Canterlot, Twilight and Company travel with two friends back inside the book to worlds that are created by music. 3rd instalment of this series.
When they discovered the mysterious Book of Disney and experienced their first adventure inside it, they are ready for more. This time, the story about a puppet that came to life. 2nd instalment of this series.
(Story idea requested by A Man Undercover, takes place directly after "Amending Fences" for obvious reasons.) Twilight realizes she's yet to apologize to Lyra for being a bad friend, and so she pays the unicorn a visit upon returning to Ponyville.
When the Fourth of July arrives, Celestia prepares for her annual battle against George Washington to prevent the end of the world. But when Twilight interrupts their battle, the Element of Patriotism must join his enemies to save Equestria.
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.