The story is complicated and dynamic but never messy. The layer of the story is thick and strong, so the writer can go deep, get out, and direct other ways without confusing the audience. Everybody is suspicious in the beginning (even Yoon-young's mother and father), but it eliminates suspects list one by one and still maintains thrill and tension till the end. What a balance. I love humor and wit sprinkled on top of the very important subject with heart-wrenching narrative. Ironically, the first two episodes and the last one are my least favorite because they have some logical errors in the timeline, but the level of attraction and concentration once the writer and the audience share common understanding is another level. Every character matters and plays an important part in the plot regardless of screen minutes.