Nadas waits, thinking that this is probably not a trap, but still more suspicious than he'd prefer. But he keeps his eyes and ears peeled.

When Cessie finally arrives, he is momentarily speechless at her appearance. So elegant. He'd never looked like that, not until- well. Some people have all the luck, is what it is.

"Ah, good to see you!" It really is good to see her. That means it's at worst an elaborate ambush, and almost certainly not an ambush at all. Should he say 'Cessie'? 'Ms. Mithar'? Better not use any forms of address at all.
He steps in through the gate, pointedly not looking at Garn. Or at Cessie. Simply up at the keep.

"I was hoping I could prevail upon your knowledge. As regards that transportation system I mentioned to your gargoyle, I may have suffered a small case of, ah, total memory loss. So in addition to getting your professional opinion on a spell I was thinking you could perhaps fill me in on, ah, everything? Just the broad strokes, that is, I wouldn't want to impose on your time."