Princess Luna has a problem. Her elder sister is nowhere to be found, and it's almost time to raise the sun! The clues in her room point to one obvious conclusion, but in her sister's absence, Luna must assume her duties. The night princess can think of but one pony perfect for the task of tracking down her sister: her most faithful student.

(I know some folks have been wanting a Celestia chapter of my fic 'A Pony Walks into a Bar', so think of this as kind of a spiritual successor to that hypothetical chapter.)