Moondancer has a plan to get away from it all. Minuette has a similar plan, only hers just involves joining Moondancer on her airship and hunting for a fabled lost treasure. Moondancer has a few problems with Minuette's plan.
Twilight's just a little nervous. It has nothing to do with Moondancer taking over the Castle Library. Or Moondancer's smile when she suggested taking over the library. Or anything to do with libraries. It's nothing. Nothing at all.