When you make a mistake, it hurts. When you try to apologize, it can hurt even more. When Gabby Gums made a mistake, she–or, rather, they–ran from it. This is what followed. AU "Ponyville Confidential" ending.
When the Cutie Mark Crusaders realized the error of their ways in the Gabby Gums incident, they made it clear to Ponyville how sorry they all were. An apology letter was printed for the final Gabby Gums article, apologies were made, and punishment dealt towards the blackmailing Diamond Tiara.
But what if it didn't happen that way?
Overwhelmed by guilt and convinced that the town they call home doesn't want them anymore, Apple Bloom, Sweetie Belle and Scootaloo submit their apology letter and bid the town a sad farewell, vanishing from the streets without any further comment. Shocked and consumed by guilt, their friends and families start a mad search to find the little fillies and bring them home. Meanwhile, in the Everfree Forest, the Crusaders themselves find that running away is much more painful–and dangerous–than they had expected.
Idea given by Waspinator331, written by request. Please show him some support.