Fan Casting "The Son" in Batman: Dark Knight's Pain

The next day, while preparing for his confrontation with the Joker, Thomas sees a horde of people on the doorstep of Wayne Manor, and after getting dressed in a proper fasion, he goes down to meet those who plan to ask him the questions they want to ask, when he suddenly bumps into a young man who burst into the building. The man apologizes for bumping into Thomas after getting back up, but then, Thomas finds himself staring at the man in shock, before uttering only one word. "..Son?"