It hasn't been shown yet, so it's anyone's guess for now. But it's possible that he knew Ah-in from before or did a background check on him before actually getting in contact with him.
I don't think it was like explained or sth. It was just hinted that he knew I believe.
something like intuition that he had been trying to develop? This is very likely to happen. If youre killing someone, being intuitive helps with idk im not a killer LOL;;;maybe like smelling fear? Hes a good actor but the fear he experienced is not the common fear we'd often feel. No matter how good of an actor you are, pulling off the act no matter what might take a toll on the body example: heavy breath/fast heart beat/trembling eyes/or even cold hands
Oh! Thank you for the explanations!
Im rlly dumb can someone explain to me how he figured out he wasn't actually blind? I probs just read it too quick :')