Will Halstead and Hailey Upton Crashed the Latest Chicago Fire—Here's Why

The One Chicago universe is prone to a crossover moment every now and then, and in the latest Chicago Fire (Season 11, Episode 17, airing March 29), we got an appearance from two heavy-hitters: Will Halstead (Nick Gehlfuss) from Chicago Med and Hailey Upton (Tracy Spiridakos) from Chicago P.D. 

Here's what happened in the episode: Violet (Hanako Greensmith) and Brett (Kara Killmer) become stumped on a call when a patient is acting erratic, has an elevated heart rate and blood pressure, but no clear-cut reason. Once he's sent to Med, they chat with Halstead about his symptoms. Normal, right? Not even close, because several days later another patient is rushed to Med with the exact same symptoms. And get this: so is the first patient's wife! 

Because Brett is brilliant, she remembers the first patient saying they took medication for a headache before the illness started. What if the medication is causing these reactions? Brett's theory proves even stronger when we learn the first patient's wife took the same medication before experiencing her illness. 

Brett has a sinking feeling something sinister is going on, like the medication was tampered with at the drug store before it was purchased. Enter Upton, who does some sleuthing and learns exactly that: A whole batch of pain medication was contaminated on purpose. The perpetrator responsible is swiftly arrested, but the entire situation leaves Brett and Violet shaken up. What's life if you can't even trust your local pharmacy to have safe over-the-counter headache meds? 

The storyline was brief, but it was great to see Halstead and Upton interact with Violet and Brett. More episodes like this, please! 

Watch Chicago Fire on NBC Wednesdays at 9/8c and next day on Peacock.  

Brett Saves a Man Who’s Been Shot with an Arrow | NBC’s Chicago Fire