A young boy appears in Equestria, and is befriended by the local party pony. Being Pinkie Pie, the first thing she does is throw him a party, but things go wrong when she realizes that nopony else can see, hear, or touch him. Now her friends are worried that something is terribly wrong with her, and they all want to help.

Pinkie knows her friend is real, and she knows she's not crazy, but where does he go when he keeps disappearing?

Inspired by the song of the same name.