When we slid into Pinkie's Party cave, some of us learned Pinkie's party plans. But when I got to read my dossier, in private, I learned something that might change the trajectory of my entire life.
Starlight Glimmer destroys Equestria when she learns how she actually lost her soulmate, Sunburst. Fixing her mistake, she learns time travel can lead to a revelation of the heart and the renovation of harmony. (An alt-ending to The Cutie Re-mark.)
The magic pony map had seemed satisfied that Pinkie reminded me about friendship. I now realized it had also sent Dashie to show me the Idol of Boreas to finish the process Pinkie set in motion, namely having me save the griffons of Griffonstone.