'Chicago P.D.': Tracy Spiridakos Breaks Down Upton's Harrowing Ordeal and What's Next (Exclusive)

The actress talks to ET about Wednesday's episode.

Spoiler alert! Do not proceed if you haven't watched Wednesday's episode of Chicago P.D.

It's fair to say Upton will be forever changed.

On Wednesday's return episode of Chicago P.D., "Still Water," Upton (Tracy Spiridakos) witnessed a terrifying car crash that lands them in the freezing Chicago river and risked her own life to save the passengers. But with the clock racing against her, she was only able to save one of the two victims. After learning that the one she rescued was responsible for the accident that led to the death of the other passenger, the guilt that stays with Upton became visibly apparent. 

The timing of Upton's experience came at a bittersweet moment for her. Newly married and celebrating 10 years on the force, Upton struggled to come to terms with the fact that she saved the perpetrator instead of the victim in a split-second decision that will be something that sticks with her for a very long time. 

ET spoke with Spiridakos recently over Zoom about Upton's roller-coaster ride of emotions throughout her ordeal, conflict for Upton and Halstead and her favorite moments from the episode.

ET: There's a lot going on with Upton internally during this episode. What was it like charting her progression once she realized who she saved?

Tracy Spiridakos: I think that that was exactly what I wanted to make sure I stayed on top of because we shoot out of sequence so much. So just wanting to make sure that I knew at what point we were at in the story, to know where she is emotionally. Just making sure I tracked that and stayed on top of that was definitely -- not a challenge -- but that was something that I wanted to be on top of. And especially that moment when we're watching the video [of the abduction] together. I also thought it was kind of cool how it was. Everybody else had moments looking away, but Hailey couldn't look away. And that was a [showrunner] Gwen [Sigan] note. Hailey couldn't look away, just kept staring at the screen, not believing what she just [saw] -- everything that just happened. Everything hitting her in that moment.

How do you think this experience will affect Upton moving forward? 

For sure up until the point where she's really beating herself up and then she has that conversation with Platt. I think Hailey is somebody who's going to continue to hold herself accountable. But I think it was a good conversation to let her maybe be a little bit kinder to herself in that moment. Not knowing, obviously she didn't know who she was saving. But we see it at the end of the episode. Even though she's had this conversation with Platt at the end of the episode, she's around everybody and everybody's meant to be congratulating her on 10 years on the job. And she's not quite there. She's still just sad and trying to figure it out. I don't know that that's going to go away. I think that's just a part of her now. 

Lori Allen/NBC

Have you seen a shift in how she operates following this episode? What can you tease moving forward how this experience has shaped her?

Unfortunately, I don't know too much about what's coming up. Apparently Halsted and I have some conflict. We just finished filming this episode a few weeks ago -- two, three weeks. So we're only one or two past that. I'm not sure what else is coming up. But I know there will be conflict for sure.

Upton and Halstead reached some important milestones. For one thing, they eloped. What are your feelings on where they stand?

I will say that when the proposal happened, I was really interested to see how the marriage portion was going to play out. Just because I can't see Hailey or Jay be big wedding people. I was interested to see how it was, how that part of the story was going to be told. I really loved the choice that Gwen made because I feel like it's so true to them. The fact that they eloped it was just that for them. And I think that the bond that these two have is really special. There's the friendship and the partnership being there for so long and then the romantic portion coming later, that I think they have this really solid thing. I know that there's going to be some conflict coming up. But, I like that there's a brief moment right now where it's kind of OK for the moment. And in this story, particularly, he's there for her and supportive. But this is Hailey's story, this particular one. That was my kind of my favorite thing this season was seeing how Gwen created the wedding and how that story was told. I really liked that.

What are you looking forward to in terms of exploring further with that relationship?

I'm interested to see just how everything that happened at the beginning of the season. We haven't really gotten to see too much of how it's affected Jay and it has. I feel like that's going to be where a lot of conflict is going to come in, is just seeing what happened with Roy earlier in the season and how that affected Jay. And then how that has shifted who he is and how he's approaching things. How will that then affect how he and Hailey interact? I'm interested to see that dynamic and just where that all falls. I don't know that that's the conflict going forward, but I imagine.

Is there a moment in this episode that stood out to you?

I'm kind of the worst at watching myself. I watched the opening and I'm like, "Oh God!" But 'm excited for the beginning portion with Atwater and Hailey. I love that there's this really fun moment. We get to see Hailey be a little bit funny and their dynamic together, which I think is different. I personally loved filming in the [water] tank. Like the underwater stuff was so cool, so fun getting to do. Then watching that come to life was really cool. I like that there were a couple moments at the end, there's a bit of levity with everybody being together. I like that it doesn't quite [end in a nice bow]. Hailey still has this sadness [at the end of the episode]. 

Chicago P.D. airs Wednesdays at 10 p.m. ET/PT on NBC. 

To stay up to date on breaking TV news, sign up for ET's daily newsletter.