Mysteries and secrets were all Dan-Han could see around him. Secrets that would wreck and shatter a wide range of people if they were all brought to light.
Puzzles seems to keep stacking up for him, and as much as he loves solving puzzles and unraveling mysteries, he was beginning to fear the outcome of the ones at hand. But he wasn't scared for himself but more for the people who were somehow involved in all this, and at this point it was, Eun-sun.
He didn't know how that has happened, but she has just be added to this huge mesh of mysteries on his plate.
He had not expected Song-Hee's answer to be what it was, and as a matter of fact, he wanted to live in doubt of it, but he knew he couldn't.