What an acting master class from Jang Na Ra. She was so impressive in this role, and I was so emotionally invested in her character from the outset. This was so intense and unpredictable, it did a great job of making me feel unsettled about what was going to happen next in the same way our unreliable narrator protagonist was. I thought the treatment of the FL's mental illness and childhood trauma was tender and sensitive and really moved me. The plot does get messy in the final episodes, it was overly convoluted and contrived in some respects, and there's one prominent supporting character I completely lost track of his motivations as the show progressed. However, they got the most important thing right, which was the FL's character arc.