The most mysterious episode, that is, the first episode, Xinyi and Mao Lilan went to the amusement park to play and overheard the transaction of the mysterious black dress person. They were found drugged and woke up to find themselves children, which is the beginning of the story line.
What impressed me the most was episode 5 1, the murder case in the library. The curator hid the body in the elevator and deeply remembered the scene where the curator was killed in the monitoring. Whenever I think of that cold expression, I feel terrible.