Celestia gives a confused Twilight some counsel.

When Starlight Glimmer reads A Hearth's Warming Tail for herself the day after Hearth's Warming, she finds it to be a bit different then how she remembered. Specifically, what was Sunburst doing in the story?

Twilight had mentioned that they could keep fighting for all eternity. Starlight didn't realize that she was actually serious about it, though.