After visiting 50 new dimensions,the cast decides to revisit those dimensions,starting with the My Little Pony Dimension.During the visit,Melissa is upset that she's the only Lil' Spark that didn't become a Fireside Girl yet and get into an arguement with Apple Bloom.Just when things seems peaceful,a new villain has arrived.A spirit name Discord,an old foe of the ponies appeared.He attempts to spread chaos all over the universes.