Circle was the most complicated drama I have seen this year. The reason I said it was that this drama was difficult to predict. Really drove me insane! I really could not piece out the puzzle until the last three episodes. Yeah, I think my brain was not able to keep up especially that in each episode, the story was told in two different years. The first 30 minutes focused on the present world while the last 30 minutes on the year 2037. It felt like watching two different stories in a drama. Thankfully, Orion and Drama Panda were available to explain exactly the story was.