Applejack comes across a Pinkie duplicate hiding beneath her barn wreckage. But, somehow, this one is different than all the others. She calls herself Pinkamena. Takes place right after Too Many Pinkie Pies.
After a decade of being trapped inside her own mind, Pinkamena takes control of her own body, happy to live life. Unfortunately for her, Pinkie Pie's friends want their friend back.