The episode begins with a flashback of officer Suranjan Sen struggling to save sub-inspector Abida. Cut to the present, Ruby, a pregnant sex-worker, is found murdered, and officer Sabir Ahmed sends the body to the morgue. Later in the night, some people secretly try to take her body out of the morgue, while being watched by Suranjan Sen.

In this season finale, Suranjan returns home to find Farzana lying in a pool of blood. The team arrests Shaukat for her murder and is surprised when Gaurav threatens to arrest Suranjan, instead. However, in a dramatic turn of events, the truth is revealed. Later, the team is ambushed while Maya is shot at, and Mira is kidnapped.

Bajraj and his wife run a prostitution racket at a shelter for rescued teenage girls. Jhuma, one of the girls from the shelter, manages to escape and reaches Mira’s house. Meanwhile, an unknown woman takes off Aslam's oxygen mask in the hospital. Sabir allows Farzana, who is brought in for questioning in connection with the murder, to leave but keeps her phone.

Farzana, a sex worker, retrieves Ruby’s body from a pond with the help of driver Govind. The doctor at the morgue retracts his first claim about Ruby’s death. Meanwhile, Sabir’s daughter Sana is kidnapped, and Suranjan’s girlfriend Maya gets a mysterious threat call. Officer Monsoor arrests Aslam for kidnapping Sana and for the murder of Ruby, and he leads them to Gazi.

Mira manages to rescue the girls from the shelter and later enquires about Abida from Suranjan. Upon reaching his house, Suranjan is surprised to see Maya and gets suspicious of her when she gets a call from a mysterious person. Meanwhile, in another gruesome murder, a family of four is brutally killed.

Another young man is found dead on the highway, and the reason for death is the same as that of the previous victim—asphyxiation. Suranjan and Mira visit the parents of both the victims to find out if they were romantically linked. Gouranga accompanies Mira to meet the victims' friends. Meanwhile, Shaukat, Gazi’s right-hand man kills Govind, the matador driver.

After being insulted by the DC, Suranjan goes to his favourite drinking joint, where Riju comes looking for him. Suranjan tells Riju about Haran, a father who raped his mute daughter and fooled Suranjan into prosecuting his innocent brother, Paran. On their way out, Riju is shot by Rachpal Singh’s man.

The highway murders turn out to be the work of a predator. Riju and Mira work with Manoj, a cyber specialist, to nab him. The team sets up a trap using Sabir as bait and catch the murderer who is a rabid homophobe. Parallelly, Gazi and Shaukat are on a mission to eliminate all possible witnesses of Ruby’s death, including Farzana.

When Suranjan’s team is called in to investigate the murder of Shankar, a drummer, the murder weapon they recover is a pair of female underpants. The cops interrogate the drummer’s wife and his band members. After Aslam is released from jail, he is shot by unknown assailants and taken to Farukh's nursing home.

While investigating the family's murder, Suranjan's team is attacked with bricks and bottles by a few kids when they try to find out what the kids are watching on a mobile phone. The cops manage to retrieve the phone and see a disturbing video. Later, a young man is found dead in an expensive car on a highway.