Upton and Ruzek are spending the morning together when they respond to a nearby robbery, which turns out to be a brutal heist of a perscription drug van.
Intelligence tries to pinpoint the crew responsible for stealing drugs and re-selling them on the streets.
They narrow their search down to a man named Eric Shaw.
Ruzek goes undercover and tries to make a major buy from Shaw.
Shaw agrees, but when it's time to pick up the product, Shaw asks Ruzek to get in his car and pick it up somewhere else.
Ruzek tries to feel out the situation, but Upton doesn't feel comfortable with what's happening and slyly sends a cop car to "drive by" spooking Shaw and his men.
Ruzek is upset that she foiled his buy, but she stands by her decision.
Shortly after, they pinpoint a drug house belonging to Eric Shaw's uncle.
They watch a sale go down and pursue the dealer who runs onto the CTA Red Line tracks and gets electrocuted.
They search the buyer, a woman named Gina, who swears this is all a misunderstanding.
And she's not lying.
Tests reveal that the drugs aren't recreational but rather medicinal.
Gina was kidney failure and was purchasing a life-saving drug that would otherwise cost her $40 thousand dollars a month.
During her interrogation, Gina swore she didn't know the man she was buying from and refused to help if it would diminish her supply.
However, a quick search revealed Gina's husband was Eric Shaw's cousin.
Her husband matched the description of the man hitting all the delivery vans.
He also worked for a company that allowed him access to all the delivery routes.
Upton advised Gina to "tell whoever is doing the robberies to stop" hoping that Gina's phone could lead them to Riley.
And sure enough, Gina took the bait.
They responded to a robbery in progress not long after and found Riley trying to save a pharmacist's life.
When they took him in, Riley said he was simply trying to save his wife's life and that Eric Shaw killed the man.
Intelligence asks Gina to wear a wire and get Shaw's confession on a recording.
Gina is successful, but when she's inside the house, Shaw threatens to kill her.
As they try to save Gina, Upton is shot in the leg.
At the end of the episode, Platt has a heart-to-heart with Upton and advises her to end things with Ruzek if he's not worth giving up a career in Intelligence.
Upton and Ruzek chat and agree it's beneficial for the both of them if they take a break.