One of the very few dramas that hooked me in from the very first episode. I binge-watched the first four episodes without a break. I couldn't stop watching. It's a sort of mixture of science fiction and mystery. I also love the way that it has a strong female character who saves the male protagonist on multiple occasions, so there's no 'damsel in distress'. Not to mention the fact that it stars the jaw-droppingly handsome Lee Jong-suk.