After a rocky Season 4 in which Casey entered politics and came thisclose to having an affair with his political adviser, and Gabby adopted a child and came thisclose to ending things with Casey for good as a result, the couple enters Season 5 on firm ground, both fully committed to raising young Louie.
"Now they've got a kid in the midst of everything else that's going on," Spencer tells TVGuide.com. "I think it's definitely made them stronger. Casey was not [initially] down with the idea of adopting a child, [but] not because he didn't want kids. It was sort of this back and forth of, 'Are we ready? Are we not ready? What are we doing?' But I think they're pretty tight [now]. ... It's just an adjustment period. I think it's trying to adjust to having someone that you really must love unconditionally and look after and think about the future. It's something [Casey's] always wanted; it just sort of came in a way that he didn't expect. But sometimes things like that are good."
For Dawson, motherhood means that she will mull a return to her old stomping grounds, Spencer says. "To have two people running into burning buildings is not great, because both of us could get hurt," he explains. "Not that being an EMT is safe, but it might be a little safer and it would work better. So she will probably go back to ambo, which will be sentimental to some of our viewers [who have watched] from the start."
Of course, the ultimate question is still whether we'll see a Casey/Dawson wedding in the future. "Maybe," Spencer teases. "I thought it would have already happened by now, but it didn't. Maybe this season, if they can hold it together."
Watch the video to get Spencer's take on what a Casey/Dawson wedding would look like.
Chicago Fire returns Tuesday, Oct. 11 at 10/9c on NBC.