A broken-spirited Spike waits for news of Twilight after an accident lands her in the hospital, dancing on the fine line between recovery and the unspeakable.
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.
Mister Lonely Heart is a changeling "Grievance Councelor", who imitates ponies that his clients have problems with. Applejack wants to say a few choice words to a relative. A dead relative.
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.
Her whole childhood, Derpy had been ridiculed because of her deformity. Dark clouds had surrounded her. All she needed was a Silver Lining. For even the smallest bit of light can snuff out the dark.