This is an alternate timeline set in the same universe as The Ties that Bind -- a "what if?" scenario, or "sister story" if you will. Reading The Ties that Bind is not required, but it is recommended.
On a cold winter night, tragedy befalls Twilight's family and she barely manages to escape with her life. Now she's lost and alone in a place she doesn't recognize.
She's left to wander aimlessly with nothing but the dark memory of that night to keep her company, but that's about to change.
Something awoke in the lavender filly that night -- a new kind of magic she's never had a chance to study before, and she soon finds she's not the only filly with dark memories and something new to learn.
Thankfully they both come across a strange town with a pony that just might be able to cultivate their new talents.