Tux Belle, the brother of Rarity and Sweetie Belle, is on his way to Ponyville to see old friends and meet his sister, both old and new.

But Rarity has different feelings about seeing her brother as he was put in a mental ward for 13 years. His cutie mark having a unnatural crack in it messing with his state of mind.

Worst of all is the reason he was sent to the ward, the strange crack, is genetic.

And a certain filly may have it.

(I suck at descriptions so make sure to read chapter one to see if you will like it.)