After helping save Hope Hollow from a drab colorless existence, Rainbow finds that her two newest friends, Pickle and Barley Barrel are lifelong orphans. She gets it in her head that she'd be a perfect new guardian for them and with a lot of help from Twilight and Celestia she gets fast-tracked for superseding adoption papers much to the joy of the two siblings. The future looks bright as they head home together but Rainbow quickly finds that the twins have a penchant for dangerous thrill seeking possibly even worse than Scootaloo. Seeing flashbacks of her adopted little sister's untimely demise, she's determined to keep history from repeating itself. As it turns out, there is a biological explanation for their behavior and an answer for how to correct it and that answer is lots of incest. Rainbow's duty is clear.