This story is a sequel to A Certain Magical Friendship - MIRROR_NOISE
After the disastrous fight with Accelerator, Twilight just wants to forget about that magical hole in the Everfree. She won't get her wish as an Extinction Event walks into Equestria. Who is 'Deep Blood', and why does she want her Cutie Mark removed?
This story can also be found on Spacebattles, Fanfiction.net and Archive of Our Own.