Rarity and Spike head off into the Everfree Forest at night to find a rare type of diamond for a dress order and encounter a Changeling. After Spike remains victorious, they head home. Shortly afterwards, another Spike turns up, and Rarity must find out who the real Spike is.

Also, I have no Spike and Changeling picture, have a somewhat relevant picture.

EDIT: Made a few changes, thanks to MetBoy's suggestions.

(Comments and Criticism are appreciated as always.)