With a familiarity of the castle that the guards envied, she skipped the normal route, preferring service hallways for their directness whenever possible, and occasionally going up a flight of stairs to one hallway, then back down at the other end, to avoid some obstacle that she expected would slow her.  The group eventually arrived at the doors outside Celestia’s private office, where she was going over end-of-year paperwork with the Royal Castellan and Royal Bailiff, ponies both well-known to Twilight.