It started off weak with the most generic start of a time altering media. It got better for a short time once the time shenanigans started until things became really sloppy and predictable. There was too much focus on the butterfly element which left no room to work on the characters. Then for the last 1/3 there was no more time shenanigans and it became purely lukewarm politics while trying poorly to figure out how to stir it towards the end. I didn't expect anything from the ending anyway. Lee Seo Jin was alright I guess.