Set during 'The Cutie Re-Mark' as Starlight Glimmer attempts to stop the rainboom and change the future with her magic scroll. But something goes horribly wrong. There is a bright flash and a shockwave felt all across Equestria. Now Spike is stranded in the past and the Twilight he knows is nowhere to be found. Spike teams up with filly Rarity in an attempt to get fate back on track. Meanwhile the other mane six fillies face new problems of their own without the rainboom to guide them. Worse still, the fallout of that bright flash now known as the 'Starburst Event' threatens to reshape the future of Equestria in a way that nopony could have predicted.
Hiatus info: Part 1 is completely uploaded. Now I have to go and write Part 2. This is going to take a while, of course. (No more deadline promises - I learned my lesson.) Bear with me during this time and feel free to continue giving feedback on Part 1 because I will still be hanging around and reading comments.
Just a warning that the comments section does contain spoilers.