After marrying Feng Shuanghuan, Shi Bi seems like a great guy to outsiders—he often takes his stepson to and from school and won’t even let Feng Shuanghuan roll out dough. Then he gets a call from Deng Ligang about upgrading to the second-generation ID card with fingerprint information. Deng Ligang warns him to keep his ID safe, because losing it and then having to re-record fingerprints could be disastrous. Deng Ligang spends most of his time in the massage room on the second floor of the pool hall. Sensing danger, he rarely goes outside and keeps a knife under his pillow.
Peng Zhaolin’s team has tailed the four criminals for several days. Finally, they catch sight of Deng Ligang—the man who still haunts Peng Zhaolin’s nightmares. Plainclothes officers stake out Shi Bi and Feng Shuanghuan’s tea shop, while Zhen Zhen and others keep an eye on the kindergarten near Song Hongyu’s son. Song Hongyu and Deng Ligang don’t often live together—he usually sleeps at the pool hall. Zhen Zhen can’t wrap her head around how such evil people could still have families. How could someone as vicious as Song Hongyu be a mother? Peng Zhaolin points out that, even though she’s a murderer, Song Hongyu still has the right to be a mom—understanding this will be important for future cases.
After several days of surveillance, the police have a complete picture of the four criminals’ daily routines in Suilu. Peng Zhaolin devises an arrest plan. Ideally, they’d capture the ringleader first, but because Song Hongyu, Deng Ligang, and Shi Bi live so close together, going after Deng Ligang alone could tip off the others and blow the operation. So the plan is to grab all four at once. Zhen Zhen looks at their photos, trying hard to calm herself.
Police locate Da Shun’s partner at the slaughterhouse and learn Da Shun has been diagnosed with cancer. The partner knows nothing about Da Shun’s real identity, let alone that he’s a killer. Officers, posing as supermarket buyers, head to the slaughterhouse to inspect the meat and seize Da Shun. Another group heads to Feng Shuanghuan’s shop to “cause trouble.” Meanwhile, Peng Zhaolin and his team surround Deng Ligang’s pool hall, while Zhen Zhen and others watch Song Hongyu. Realizing she’s being watched by the police, Song Hongyu quickly disguises herself and flees. Peng Zhaolin moves into the second-floor massage room, where Deng Ligang is lying in wait. After pinpointing his exact location by phone, they break down the door. Deng Ligang, fully prepared, instinctively reaches under his pillow for a knife. In the ensuing struggle, he escapes up to the rooftop.
Song Hongyu darts through narrow alleyways. The moment Zhen Zhen hears the chase is on, she can’t just sit back. Summoning her courage, she goes after Song Hongyu. Upon being confronted, Song Hongyu pretends she doesn’t recognize Zhen Zhen, but Zhen Zhen will never forget that kidnapping. Now a police officer, she arrests Song Hongyu on the spot.
Deng Ligang’s attempt to flee also fails—he’s cornered by Peng Zhaolin. The police have the place sealed off tight. Deng Ligang makes one last desperate move but slips from the rooftop. Peng Zhaolin catches him, refusing to let go—at least not until Deng Ligang faces the law.
