I had no expectations honestly because the drama was so overhyped even before it was released. But I watched it still because that is what all ever talked about on Twitter. Amazing how the parallel world concept was used, it is not predictable at all, see you don't know what's going to happen next. The original soundtrack adds up to the dynamics of the scene. Superb acting by the cast. Chemistry of the leads is to die for. I can't count how many times I was mind blown away by this drama. It's difficult to understand but only if you are not smart enough.