"You have no idea." An innocuous phrase (said with a touch of irony, resignation and possible regret) but one which has been showing up in a wide variety of situations often enough to be noticeable.
As Tarvek Sturmvoraus prepares to leave his home with Lucrezia's party, he comments, "It's difficult, leaving... all this behind. Not knowing when I'll return. You ever get like that?" Since his back is turned, he misses seeing the odd expression cross Lucrezia's face before she turns away with a wry grin and replies, "You have no idea."✣ Considering Lucrezia's apparent lack of any sort of regret over her known actions (destroying much of Europa, banishing Klaus Wulfenbach, losing her firstborn), this is a curious reaction and begs further revelations.
Agatha makes her way through the Castle, with the Chapel guiding her as she hunts for Gilgamesh Wulfenbach so he can treat Tarvek's wounds and odd color-change; as Gil has just completed his repairs, the Castle's awareness has been extended, but not its control. Agatha, vexed at the slow progress, grumbles, "How annoying". The Castle replies, sotto voce, ""You have no idea,"✣ then continues in its normal tone to give her the directions she needs.
