What would you do if you arrived in a place you'd never been before, only to find that you'd been living there for years? The Doctor's solution is simple, but, involving as it does him interacting socially with other ponies, is unlikely to work...
The Doctor, newly regenerated and rather helpless, is shocked to discover that his place of exile isn't quite as safe as he thought. An old enemy has returned to Equestria, and only the Doctor and his new 'friends' stand in its way... Oh, crumbs.