[Warning: The following contains spoilers from Wednesday's episode of Chicago P.D. Read at your own risk!]

A teen opioid crisis brought the first responders of Chicago Fire and Chicago P.D. together for a two-hour event, which also featured the long-awaited return of Sean Roman (Brian Geraghty). The hour saw Roman head back to town in search of his younger sister, who'd gone missing amid a string of overdoses. After teaming with Fire's Severide (Taylor Kinney) and later P.D.'s Intelligence, Roman eventually found his sister dead in a backyard.

An understandably upset Roman tracked down and killed the man responsible for his sister's brutal murder, an act that should have landed him a lengthy prison stay. Burgess, who was conflicted about whether or not to turn her ex-boyfriend in, ultimately chose to do the right thing and arrest him after his sister's funeral. But it was Voight (Jason Beghe) who intervened in the last minute and allowed him to walk away as a free man.

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That wasn't an easy decision, and Voight only changed his mind after hearing Roman's haunting eulogy for his sister in which he contemplated grief and guilt over what he'd done. According to showrunner Rick Eid, different endings were considered before they ultimately landed on Voight letting Roman go.

"We considered having Voight arrest him at the end, and then we thought about him not arresting him at the end, and then we thought about what would he really do? Then, based on the eulogy and where Roman speaks about there's no such thing as absolution and you carry around with you what you've done forever... I think, in Voight's mind, that was enough of a penalty or a punishment for what he did, and that was the thing that sort of pushed him to not arresting him," Eid explained.

That open ending certainly leaves room for Roman to come back and Brian Geraghty, who plays the former cop, seems open to the idea. "I couldn't have asked for a more better way, at a better time to come back," he said, noting that he's "absolutely" open to reprising his role and potentially exploring Roman "trying to be a cop again," or a relationship with Burgess (Marina Squerciati).

If Roman does make his way back to the Windy City, don't expect the latter to happen. Eid, who said he hoped we haven't seen the last of Roman, noted that Burgess and Roman finally achieved a sense of closure after breaking up in Season 3.

Marina Squerciati, Brian Geraghty, <em>Chicago P.D.</em>Marina Squerciati, Brian Geraghty, Chicago P.D.

"I think there were a lot of unresolved feelings about him leaving that they didn't communicate. She felt that he just moved on and ignored her. I think, by the end, they realized how much respect and admiration they have for each other," Eid explained. "I don't know if they are romantic feelings that've been sparked; I don't think so. I think it's just more like their friendship is back on solid ground and with a new, deeper understanding of each other because they both shared some intimate thoughts and experiences with each other, probably on a deeper level than they had, even when they were closer. So I think that the mutual sharing of these really personal, painful things brought them much closer."

Besides, Burgess has enough on her mind after suffering a miscarriage while on the job. In an intense locker room scene with Ruzek (Patrick John Flueger) toward the end of the hour, Burgess unloaded on Ruzek after noticing he kept a photo of their unborn child's sonogram taped to his locker. Although Ruzek doesn't blame Burgess for what happened, Burgess is still struggling with her decision to enter that motel room without backup, which resulted in her losing her baby. As they both continue to grieve, the remaining episodes of the season will see Burgess and Ruzek trying to find a way to co-exist.

"Their feelings for each other are undeniable. They really care about each other and they both wanted this baby. It started off in an unusual way, but, by the time they both got their heads around it, they came to a place of, "This is great," and they were both genuinely excited about it. Then, when it went away, not only did they lose the baby, but they lost this future they were both counting on," Eid said. "Will they be able to create a new future with each other? That's the question we're trying to explore: what does their future look like with each other? When they put all this pain and emotion behind them, will they be able to reunite in a romantic way? [And] as colleagues, what does it look like? We're exploring all of that."

While Burgess and Ruzek attempt to recover amid tragedy, things might heat up for another romantic pairing. Upton (Tracy Spiridakos) came close to revealing her feelings to Halstead (Jesse Lee Soffer) earlier this season, but backed down when a phone call interrupted their conversation Since then, the pair have remained strictly professional but according to Eid, things will finally start to pick up between them.

"I think that their strong feelings for each other will ultimately present themselves in some sort of romantic way," Eid teased.

Brace yourselves, it looks like Upstead may soon take flight.

Chicago P.D. airs Wednesdays at 10/9c on NBC.

Jesse Lee Soffer and Tracy Spiridakos, <em>Chicago P.D.</em>Jesse Lee Soffer and Tracy Spiridakos, Chicago P.D.