[I'm sorry for my poor English, I hope it's good enough for you to read without any effort]

First of all, this drama is HUGELY underrated. I've rewatched it 5 times, and I'm planning to watch it again very soon (so if you're wondering if it worths a rewatch, it's definitely a YES!).

It's not a zombie story, it's not an horror story. It's more like a story about people trying to fight against prejudice, poverty, injustice, weakness, illness, fear.
Every single character has its own role in the story: no one is unuseful, no one is replaceable. Rich and poor, healthy and ill, good and bad, kind and rude, old and young, brave and coward,... And nobody is 100% how they seem, they only reveal their own nature when they or those who they love are in danger.
You'll soon discover that the main characters in Happiness are the people, not the monsters.

Let's focus on the title. I decided to watch it only for its title, without reading the plot. It's not a "happy" story, but every character is looking for its own happiness. Some of them think that true happiness is purchaseable, some others just look for their place in the world. The truth is that nothing is certain: every thing we want may not be what we really need, or it may be that something we take for granted is what we really want.

I've loved the cast! It was my very first drama with Park Hyung Sik, and he literally blinded me with his incredible talent. Han Hyo Joo is stunning as always, and their chemistry on screen is fabulous: their presence is absolutely balanced. I was genuinely happy to see two strong, brave and kind main characters: no damsel in distress or charming prince, they're equal.

Last but not least, I've also loved the music! Joe Layne was a huge surprise, and I still listen to his OST almost every day. Pain and Enigma are on my playlist as well.

What other can I say? Don't focus on the "horror" side of the story, just enjoy it!