Wow, just when you think you know what's going on, they throw in another curve ball. This, for me, required a lot of attention, because there were a LOT of moving parts, and the "good guy/bad guy" dynamic changed quite often. I thought the script was excellent, the actors were great, and I'm SO glad I watched it. Below are random musings...

1) Woo Do Hwan as Kim Min Joon. There are moments you think you might want to hate him and his selfishness, but you just can't. I think Do Hwan is the centerpiece of any show that he is in. There is something so charismatic about him that just commands your attention. His vulnerability, his bravado, his humor, his looks. This man is the whole package. You might forget to breathe when you see him smile, but when he cries, you would like to hold him.
2) Yoo Ji Tae as Kang Woo. He was great in this as the leader of the Mad Dog team, how he wanted to be a lone wolf, but the others wanted to help him and keep him safe.
3) Jo Jae Yoo as Soon Jung - I just have to say I loved seeing him as a good guy. I'm used to him as the baddie.
4) Ryu Hwa Young as Ha Ri - I really like this actress. She reminds me of Park Shin Hye, but personally I think Hwa Young is a better actress and actually has facial expressions.
5) Park In Hwan as the professor. I love this gentleman, he's just so sweet looking. If you haven't seen Navillera, watch it. He was amazing!
6) Jung Hyuk Jin as Moo Shin - he was amusing, and I'm glad he was on the side of good throughout.
7) Choi Won Young as Hyun Gi. He played a good bad guy, script wise, but I kept wishing they hadn't made him so obviously bad. Between his unfortunate haircut and his bad styling, from the moment I saw him I knew he'd be the big bad. Those stupid shirts with half of the tie going up through the collar, I kept thinking he needed to fix his collar! Not a good look. I would have much preferred that they had written him as someone that it was a surprise to find out he was bad.
8) BTS on Min Joon's ear buds when he was jogging. BTS is always a good thing!
9) The "romance" between Moon Jin and Ha Ri - I thought this was really well-written. Very understated, flying under the romance radar. The team knew that they liked each other, but the two of them had no clue. And when he sat across from her at the table and said, "I just want to sit here for a minute and look at you" - be still my heart! And she was looking everywhere but at him.
10) Soon Jung's crush/relationship with the nurse. I loved watching that relationship develop, and I loved that she was part of the team at the end.
11) The developing relationship between the members of Mad Dog and Min Joon. Here was an already tight team that suddenly had to deal with Min Joon's questionable motives. I loved the trust and caring between the team members and enjoyed watching them slowly drawing Min Joon into their circle. And when Min Joon finally called Kang Woo Hyung, all was right with the world.
12) This drama had a good mix of tension and humor.
13) My only complaint was the overabundance of corruption. A couple of people, maybe, but the corruption was rampant in this one.

I can highly recommend this one.

I normally don't care for second seasons of shows, but I'd love to see more of the Mad Dog team.