Ponies have long lived in the magical land of Equestria, and have come to know the multitude of creatures their share that land with.

Changelings are not among those creatures.

When the Queen of Changelings arrives at their doorstep, desperately asking for their help, the Magic of Friendship moves Night Light and Twilight Velvet to offer it. But that night would not be the end of the story of the mimic queen's legacy.