Kaylee was tired. She understood why the Captain and Simon were so gorram moody, really, she did. She wasn't any happier with this situation than anyone else was, but you didn't see her sitting around the ship and growling at anyone who cracked a smile. It was just plain wrong when Jayne was the one being the most positive and cheerful. Gotten so that she just wanted to lock the door to the engine room so's she wouldn't have to worry about being snapped at.
-- Camouflage Ch 6 by jebbypal