On the latest Chicago PD, Burgess deals with her very first criminal informant and proves that she's still got a ways to go before becoming a detective. 

While grilling Sienna for some useful information about a drug called "gray," she dismisses her story about a friends boyfriend who reportedly killed his ex behind the Wyatt factory. 

Upton, who is temporarily assigned as Burgess' partner while Halstead seeks therapy, sees a red flag with the story; it's too detailed and out-there to be made up. 

Burgess, however, insists on ignoring it, so Upton goes behind her back and asks her CPD friends to look into it. 

Turns out her snitch wasn't lying just to get her name cleared — they really did find a dead body behind the factory. 

A body that belonged to a girl who was beaten by a tire iron about a month ago, according to the medical examiner. 

Their only lead in the case is that both girls — the one found dead and Isabelle, Sienna's friend, who has been missing for over three weeks — had motor oil injections in their buttocks.

One of Upton's informants, Raul, does some digging and finds the fake "cosmetologists'" office, who unwillingly gives them the suspects' real name: Damien Soto. 

A quick search reveals that Soto is also the founder of Jenny's Haven, a shelter where both girls stayed at some point. 

Burgess is so desperate to find Soto and the girls that he has taken hostage in his prostitution scam, she forces Sienna to ask around with her former druggie friends. 

Even Upton admits that it's a harsh and troublesome request for someone who is trying to clear their record and stay clean, but Burgess believes that's the job of a CI. 

She quickly realizes she probably should have taken Upton's advice when she gets the call that Sienna has been found dead in a park during a deal-gone-wrong.

Sienna's passion for wanting to help her friend wasn't completely wasted though. Her phone history led Intelligence to the drug dealer, who revealed he was going to see Isabelle in a few hours when she needed her hit. 

When Isabelle finally arrived, Antonio and Burgess grabbed her and took her into custody. Unfortunately, the driver got away. 

Isabelle was so blatantly in love with her captor, they knew she wasn't going to give him up so they opted for Plan B! 

They set her up in a safehouse and gave her a phone, hoping she would take the bait and use it to call Soto. 

She did. When he arrived, he realized Isabelle sold him out and drew his gun. Thankfully, Burgess was quicker and shot him in the shoulder forcing him to release Isabelle, who was in shambles on the ground screaming, "why did you shoot him? I love him!"

Soto was taken to Med but even with his cell-phone, navigation system and other gadgets they were unable to locate the house where his "product" aka the girls were hidden. 

Upton tries to pull intel from her CI but pulls out when she realizes it would get him exposed. 

Burgess throws a fit, calling Upton out for not wanting to risk her CI while she let hers die, a choice, Upton points out was all her own. 

When Soto finally gets out of surgery, Voight and Olinsky pay him a little visit. When he refuses to talk, Voight threatens to accidentally "crank up" his morphine drip so his death looks like an accidental overdose. Talk about intimidation tactics!!

Voight then takes a play from Burgess' playbook and has one of the nurses leave a wire-tapped cell-phone in his room on "accident."

Soto takes the bait, again, and makes a call to another Pilsen pimp who agrees to buy the product off of him for $90 thousand. 

When the pimp arrives at the house, he's greeted by CPD! 

Inside they find the remaining seven girls, including the one diabetic girl who, unfortunately, didn't make it. 

Still, they need Isabelle's testimony to make a case against Soto and she's not willing to talk because remember, she's a victim of Stockholm Syndrome and truly thinks that she loves him. 

"He doesn't love you, Isabelle. He pretends he does so he can control you," Burgess tells her before getting personal about a love who never loved her back. It does the trick and Isabelle agrees to talk! 

While Burgess is spilling her feelings, Ruzek is on the other side of the one-way mirror, wondering if she's talking about him. 

Later in the locker room Upton confides in Burgess that no matter what the call, it's never easy and inevitably, someone always gets hurt and that stays with you forever. 

The two have a moment and Upton even suggests they grab dinner together to which Burgess replies, "cool."

After a long and exhausting day, Burgess and Ruzek head to Molly's bar to unwind. 

Still perturbed by Burgess' comments in the interrogation room Ruzek begins to question her story but she quickly assures him that it wasn't about him. 

He then proposes they head back to his place and at first, Burgess isn't interested, but then she realizes that a little fun after such a grim day wouldn't hurt. 

And suddenly, the Burzek kiss we've all been anticipating since the breakup happens! 

Are they a couple now? Will this just be a fling? I guess we'll see!