Perhaps Darcy's "surprise" was little acting on his part or surprise, not that it happened, but that Elizabeth was told about it since he and the colonel had tidied things up so nicely. Or, it was just that our DA wanted to use Austen's words for the scene at the inn where E reads Jane's letters...
My question is, if Jones saw Mr. Darcy when he retrieved Elizabeth how did Mr. Darcy not see Jones? Has Mr. Darcy not already deduced Elizabeth's identity? Does he at least suspect?
Poor Mr. Darcy, are you going to make him suffer through the entire little season while other men (and their mothers and fathers) fawn all over Elizabeth courting her favor? Though they're laughing about it, I imagine the duke and uncle Robert would be pleased for Elizabeth to marry a man they already know and trust (and who is slightly terrified of her grandfather!).
