Lin Xiaoman (30 years old): an emergency doctor at a municipal hospital. He has a cold personality but is hot on the inside. He lived with his mother after his parents divorced when he was a child. He has an estranged relationship with his father Lin Jianguo (a retired worker).
Lin Jianguo (58 years old): A taciturn old electrician who lives alone in the old city. In recent years, he has frequently visited an "old friend" in a mental hospital (foreshadowing).
Su Qing (28 years old): Lin Xiaoman's childhood friend, a community police officer, participated in the investigation of the demolition case in the old city and accidentally discovered that the file on the "girl falling from the building" case 15 years ago had been tampered with.
Hidden character: The "mysterious girl" who fell from the building 15 years ago (related to the Lin family by blood, the truth of her death was covered up by many parties).
Concept: Are white lies really white lies?