Alex and Maggie [SPOILER] on 'Supergirl'

Supergirl debuted a new episode tonight, and while Lena was the one coming under fire, someone else close to the Girl of Steel had their own repercussions to deal with.

Spoilers for tonight's episode of Supergirl, "Damage," below.

Alex (Chyler Leigh) and Maggie (Floriana Lima) have been experiencing difficulties in their relationship all season. Even with wedding plans running full steam ahead, both Alex and Maggie have been shown to be dealing with their own challenges and reservations about the upcoming nuptials. From disagreements over wedding details, to Maggie's harrowing attempt to reconnect with her father, to Alex's desire for children -- even though Maggie doesn't want them -- the fan-favorite "Sanvers" couple has been building up to some sort of resolution.

Unfortunately, tonight's episode revealed that that resolution is the dissolution of Alex and Maggie's relationship.

As was hinted at in previous episodes this season, the issue of children turned out to be the obstacle that the couple couldn't get beyond and according to Leigh the weight of the episode was something that director Kevin Smith took great pains to ensure was done correctly.

"Initially, when we had the table read, we actually separated all of our stuff from the rest of the table read," Leigh told ComicBook.com during a recent set visit. "So we didn't sit in that one. Because Kevin was really wanting to make sure that we do this really well. And so he took Flo and I aside, and we did the table read just with us, and Andrew Kreisberg and Jessica Queller. [We] wanted to make sure that the words were right, the intention was right, and the heart behind it was right. Either way, any way you roll the dice, it's not going to be easy. And it's something that everybody felt. Kevin also said that he thought it would be really great, and I totally agree, to do all of the scenes in one day. So it was a hell of a day. It really was. But I really feel like we can only do our best with what we're handed, right? And that goes with everything in life. And in this case, because it was so deep and so heartfelt, the day was tough. It was."

But as Supergirl's showrunners have previously hinted, Maggie could certainly return in future episodes, something that Leigh would be on board for.

"It's not like an absolute closure because no one ever knows what's going to happen, and as of now, what we know is we got these five amazing episodes." Leigh explained. "And based on availability, I know that just sounds like words, but it's just. It really does come down to that."

Nevertheless, Leigh is more than aware of the impact the storyline will have on "Sanvers" fans - something she felt by the end of the day's filming.

"I will not lie, I had a lot of wine by the end of the day." Leigh revealed. "And I had a driver pick me up and take me home. So it was a long one, but I think it was all worth it."

Supergirl airs on Mondays at 8/7c on The CW.