Decades after the last Friendship Report arrived, a burst of green dragon flame ignited the darkness in Princess Celestia's room.
Although the contents of the letter remain unknown to the public, it's been noted by servants of the Crown, that the Princess abruptly cancelled all of her visits for the day and wasn't seen until the next one.
When questioned, Her Highness simply gave the audience a bittersweet smile before explaining that she was paying respects to an old friend.
A short-story that diverges at Magical Mystery Cure.
Edited by Equimorto, with additional help by Jinxed and an Anon of /fimfic/.