There are only two episodes left in “Chicago PD” Season 4. Last week on the NBC show, the Intelligence Unit of District 21 took down a group of bank robbers. Unfortunately, these bank robbers were just teenage boys doing the dirty work for a partially paralyzed criminal.

The case took a toll on Detective Erin Lindsay (Sophia Bush) who unknowingly shot a teenaged boy. He had his mask on and was fleeing from the crime scene after robbing cash from a bank. Although Lindsay shot him in self-defense, there was no denying that she had killed a little boy.

Fortunately, the harrowing incident got Lindsay one step closer to Detective Jay Halstead (Jesse Lee Soffer). She leaned on him for comfort.

Episode 21 also introduced audiences to new Detective Hailey Upton (Tracy Spiridakos) who butted heads with Intelligence Unit team leader Hank Voight (Jason Beghe). They ended up working with Upton. In fact, the detective’s skills were so impressive on the robbery-homicide case that Voight offered her a spot in his team. With Burgess (Marina Squerciati) away on furlough, the team could really use a talented detective. Girl power!

READ: Connor clashes with Charles over Robin’s treatment in “Chicago Med.”

What will happen this week on “Chicago PD”?

Well, the team solves an interesting case in Season 4, episode 22. According to the official synopsis, the police come across a live video that is streamed online showcasing a tortured man being beaten and burned alive. Upon further investigation, the team discovers that the victim’s identity can be traced back to that of a man who had been jailed for statutory rape.

Which means, the Chicago Police Department has a vigilante on their hands. This justice seeker is torturing and murdering pedophiles.

When another attack of a similar nature occurs, the Intelligence Unit scramble to find to find the perpetrator. Soon, several suspected pedophiles are murdered. The group responsible for killing and burning child molesters call themselves the Perv Hunters.

The promo of the episode, titled “Army of One,” reveals that Detective Upton took Voight’s offer and joined the team. She is investigating this case along with detectives Lindsay, Jay, Voight, Ruzek (Patrick John Flueger), Atwater (LaRoyce Hawkins) and Olinsky (Elias Koteas).

The video shows them watching the video of a man being burned alive. They quickly rush to the scene of the crime.

It seems that children are involved in the case. Lindsay, who certainly has a soft corner for kids, questions a suspect on the location of a child. The video ends with the death of a boy. Needless to say, Lindsay is furious.

Although catching the Internet killer takes center stage for Lindsay on Wednesday’s episode of “Chicago PD,” she will be dealing with a few bumps in both her personal and professional life. Does it have to something with Jay? The couple finally looked like they were repairing their relationship last week. Hopefully, nothing happens to derail their progress.

This is the penultimate episode of Season 4. “Chicago PD” will air its season finale next week.

“Chicago PD” airs Wednesdays at 10 p.m. EDT on NBC.