I never really write review that often. But here I am. This is one of the best mystery/investigation drama I've ever watched. The characters are well developed. At some point, I thought there would be a loop hole in the plot. But the plot was perfect. I usually hate investigation dramas with single case plot. Because single case dramas are always boring and long. But this one is well made. I didn't even had time to think other things. While watching this drama I was only thinking about the mystery and it is going to end. This drama is really amazing. Don't think twice, Just watch it.