Dedue did not expect to see Claude in the doorway, but he supposes that he can take it. There is, also, some amount of satisfaction to be gained from the gobsmacked look on his face, just because it's so rare for anyone to get the better of him. Claude grabs him by the arm and Dedue allows himself to be pulled along, mostly because Claude knows where Dimitri is and Dedue's sole objective is to find His Highness again. All of the strange things that are coming out of Claude's mouth can be dealt with later, if at all. And, really, when has Claude saying strange things ever been unusual?

"Claude." He stops, which would have the added effect of bringing Claude to a stop as well so long as he still holds on to Dedue's arm. "How long has His Highness been here?"

After Myrddin, Dedue had been able to observe Dimitri's general state and found him... not well. It had been five years since he'd been able to watch over His Highness, and his condition had deteriorated significantly over that time-- muttering to his ghosts, haunting the cathedral at all hours. What would he be like now, if he had been taken from his war and his obsessions so close to Gronder, where he would have another chance at Edelgard's head?