*Edit: 26 Nov. 2014. Changed tags to 'Teen' and added 'Dark'. But it's a light-dark.
Luna wakes in a cavern, blindfolded, gagged and bound by magic runes. Her captors are exultant. They have captured the co-regent and sister to the highest power in all Equestria. They can name their price!
Or can they?
Luna won't cooperate, Celestia hasn't answered the ransom demand, and Canterlot is acting like nothing is amiss. The moon rises and sets just like it always has.
If they have Princess Luna, why doesn't anypony seem to care?