(Slight spoilers for "The Last Crusade" for those who haven't seen it yet. Tagged Alternative Universe for obvious reasons.)
It's not every day that a big, world changing secret is shared with somepony. For Scootaloo, this is one of those days.
Her mom and dad reveal that they aren't her biological parents, they adopted her when she was a little foal. But they don't know who her birth parents are.
Not satisfied with the answers, Scootaloo (with the help of her foster parents) sets out to find the truth by embarking on a personal crusade. But will she like what she finds out about her birth parents?