Trixie's been back and forth to and from Ponyville, but this time, she's come back to move in! Until she can find a place to live, however, she'll have to bunk with somepony else for the time being. With Twilight being out in Canterlot for some sort of princess-y thing, Applejack busy with the farm, Rarity taking care of Sweetie Bell, and Pinkie Pie being, well, Pinkie Pie, the only one left to take her in is Rainbow Dash. How will two of the most competitive mares in Equestria handle living together?

They probably won't handle it well, that's for sure.