I watched this show on iqiyi, and in the beginning it looked just another spy show, but it surprised me. The Substitute gets stronger and more intriguing at each episode. The best thing about the narrative is how it makes precise choices on what to tell of each story. With each episode running only 20 minutes long, and the could have easily fell into the trap of trying portray their characters with instantaneous depth, and leave all the action for later. But that would only make the episodes move slowly. Instead, there is always an assignment going on, and we fall for the characters along the way. Plus, a female protagonist with a strong personality (not to confuse with 'bossy') gives The Substitute some extra points. Seeing Lili start her career as spy makes me feel that I'm watching something different than your regular James Bond or Nikita story. It's like seeing the beginning of something big.