Wow. Without giving out any spoilers... I hope... :P, I must say that this is the most twisting and interesting drama ever! It's one where I go OMG WTF just happened and OMG WTF I didn't expect that to happen right after. I tried anticipating what would happen next and whatever happened next totally blew my mind, heh besides the fact that Lee Song Juk, or was his name Lee Jong Suk, had really fair and smooth skin and I was constantly distracted by that. Lol.
The last episode 17 which explained how they made the movie was extremely interesting.
A definite must watch drama :). 9.5 / 10. I'd give 10 / 10 if I've watched more than 10 KDramas but I've only watched 5 of em and I did enjoy all of em. Hee.