[Warning: The below contains MAJOR spoilers for Transplant Season 4 Episode 8 “All I Have Is How I Feel.”]

The most shocking moment of all of Transplant comes near the end of its fourth and final season. With only two episodes left after this one, the medical drama says goodbye to a major character.

It was only a couple episodes ago that Mags (Laurence Leboeuf) had a heart transplant and she and Bash (Hamza Haq) got back together. But in this episode, she’s been at Level 1 rejection for a couple weeks, culminating in Bash calling an ambulance and them rushing her to the hospital. However, there’s nothing they can do: Mags dies.

Leboeuf shares with TV Insider a key piece of direction she received from the episode’s director, Stefan Pleszczynski. “When they come and get me at the house and when we call the ambulance for them to come get me, he told me to start thinking that Mags was starting at this point to hear a waterfall, but that she was the only one hearing it,” she says. “And as we’re getting closer and closer to the hospital, it becomes noisier and louder. And I really liked that image because I felt like that’s what it was. She was kind of alone in this bubble all of a sudden being so good at her job. I think she knew that this was bad and going into a really dark situation. I don’t know if she expected to die, but I think she knew she was going near this waterfall that she was going to maybe not come back from. And I liked that piece of direction. I thought that was awesome. I think she kind of felt something brewing for sure.”

Read on for more from Leboeuf as well as Hamza Haq, Ayisha Issa, and series creator Joseph Kay for insight into why Mags was killed off, those final Bash and Mags scenes, and more.

Why Transplant killed off Mags in the final season

As Kay explains, Mags made a brave and ballsy decision getting her heart transplant, and sometimes those don’t go the way people hope. “She was OK with it either way. Being Mags, she’d really thought through, did she want to live essentially impaired, or did she want to leave it all out there on the floor?” he shares.

He acknowledges that the “happier” choice would have been to let her live, but instead, the show took the more dramatic route, showing, “There are consequences sometimes that suck in a medical series where our doctors are always dealing with random, unfortunate medical situations. Sometimes they’re pulling miraculous saves out, but those aren’t always on the table.”

What also factored into it was the series ending. “We wanted to shake things up and do something bold and important to our audience that would affect them and upset them and make them, sure, angry at us, but also curious to see how the rest of this journey goes. We didn’t want it to go out neatly,” explains Kay, adding he doesn’t mind if fans are sad or angry. “I’d rather you have any emotion than be totally neutral to what we’re trying to do.”

It also came down to them wanting to challenge Bash in the present after focusing so much on the trauma of his past. “We’ve described the show as a window into his life when he learns to put some of his past behind him,” Kay says. “How can we really know that Bashir is going to walk away from this period of his life a little bit better than if we see him lose something in the present and face something in the present that really shakes his foundation? And if we see that he has the tools to overcome that, then we can leave with a grounded bit of hope, not a fairytale bit of hope.”

He knows that fans had expected the series to give Bash and Mags a happily ever after, “but that was never going to be the show,” he tells us. “That’s actually why we did that in the middle of the season. We had them get back together and over the fact that she was having this surgery and create a little life for themselves that was nice. Yes, we’re doing that and ripping it away, which is unkind perhaps to those in our audience who were rooting for them and for either of them, not even as a couple but as individuals. But we want it to make you feel.”

Laurence Leboeuf’s reaction to Mags’ death

Leboeuf tells us Kay called her before work on the final season began to tell her of Mags’ fate. “I loved it,” she reveals. “As much as I was heartbroken about it, I thought it was really daring of them to do that and to do it with Mags that I don’t think you expect to do that with. I love that they decided to go down that journey and that we’re not ending this in an expected way in a sense. And so I was all for the adventure and knowing it was the last season, knowing that this was going to wrap anyway at the end, it was sort of a real way to mourn this show.”

Kay recalls Leboeuf being “really excited” about the development, which he found interesting. “She’s not thinking, ‘Oh, what if you bring this series back in three years?’ She’s thinking, ‘That’s amazing. I really want to do that and lean into it.’”

Ayisha Issa (who plays June) shares that what we saw onscreen mimicked what was offscreen, with Mags’ final episode before everyone else’s.

“I was upset about it. Laurence and I have a close relationship, and we all kind of developed a real connection to our characters and therefore to each other’s characters. And so it was really heartbreaking to know that she was somehow going to be leaving before the rest of us,” she says. “That part of the experience was very real for all of us because even though we shot everything out of order, that part actually followed in the sense of once Mags died, we no longer were really working with Laurence anymore. So it was hard, it was sad. I think we all went through an actual process of mourning as people and as professionals and as actors, as well as through the characters. A lot of what I think you see through the characters is real.”

Bash & Mags’ final scenes together

After ups and downs, it had seemed like Bash and Mags were finally in a good place once they got back together. They were then together for Mags’ ending, from the moment she realized something was really wrong and she needed to go to the hospital, to her death.

“It was a tough episode to film,” Hamza Haq tells TV Insider. “Laurence and I ended up reading the script together. We found it. They wouldn’t give us them too far in advance so we wouldn’t anticipate everything, but we’re conniving, so we were able to get a leak of it. And I think it was during lunchtime while we were filming something else and we’re reading 408. And when we both finished reading it, it was like, ‘Oh, this is good.’”

He liked that rather than being a “grand” event, “it’s approached in such a beautiful way [as] something that just happened. I think that it so beautifully talks about the fragility of life and how when it happened, it was the right time for it to happen because they had six months together. They had this beautiful relationship together, even in the way that they were talking to each other, the way they were planning their futures, the way they approached when the incident started. When she wakes up in the middle of the night and then they’re just kind of with each other and she’s grabbing the stethoscope, he’s grabbing the monitor, he’s staying with her the whole time. He’s with her the whole time. From the moment that they decide ‘we’re going to do this,’ it’s like they’re inseparable.”

Yan Turcotte/Sphere Media/CTV

Haq also noted the lesson that his character learned as a result of losing Mags after he blamed himself for not being able to save all the people he’s lost. “I think he finally made the decision that, ‘I’m going to be here for this person no matter what,’ and Mags’ death was kind of like a forgiveness of everything else because it was just like, ‘You did everything the right way. You were here the whole time and you still couldn’t save her because it was her time,’” he explains. “I think that not being able to save Mags is his big realization that ‘I actually couldn’t have saved any of them.’ The thing that he loved most, he still couldn’t save. There’s sort of a humility that comes with that that allows him to continue to take risks because it’s relinquishing control finally, maybe for the first time in his life. Did Mags have to die for him to learn that? Joseph Kay, our writer, certainly thought so, but I found that the lesson in that was just so beautiful.”

Leboeuf likes that Bash and Mags were together for the end, noting that Haq loved her character as much as she did. “We knew it was the end of the show, also, so I think that added to the emotion,” she says of filming those scenes. “At the same time, we had to play it kind of chiller. It’s not the goodbye that you expect because they don’t know.”

According to Haq, that was an emotional day on set, with the crew pretty consistent since Season 1. “Everybody was taking such good care of us in terms of, a set can be a rowdy place, but it was just the amount of weight and respect that everyone had for Laurence and for me and for the story itself. So when it was happening, we were very supported in telling a very difficult story and it was easy to get to because it was also the end of our scenes together,” he recalls. “It was the end of our time together, and we’d had such a great time telling the story of Bash and Mags. So it was in real time we were mourning that loss and the realization that like, ‘Oh, I’m actually not going to get to do this again.’”

Leboeuf is a fan of Bash and Mags’ relationship as well. “I think they both have this incredible connection since the beginning and you just want them to be together already. You’re just like, ‘You guys connect so much,’” she says. “One of our favorite scenes — and I’m going to talk for Hamza, too, because we’ve talked about this before — is I think at the end of Season 2, where he comes and knocks on my door and I just come out and we just look at each other and we don’t say anything. That was one of my favorite moments of the whole series because I loved everything that passed between us in that moment. And I think that explains that relationship. Sometimes you don’t have to say much to understand that there’s a current that’s there that’s passing and that they understand each other.”

What to expect from Bash’s grief

Looking ahead, expect to see Bash’s grief “come in waves,” warns Haq. “He’s watching other people process their grief around it before he even processes his own. And I think that it’s very much that the only way is through.”

He continues, “It’s going to be a lifelong thing, and it is certainly going to be one of those pivotal Bashir defining things that he’s going to carry for the rest of his life. And maybe we won’t know exactly how because the [series is] done, but what we will know is he’s certainly going to have the knowledge of really loving someone, losing somebody. Perhaps that’ll make him better at talking to patients who have gone through that. But I think processing grief or trauma or anything like that, that’s a lifelong endeavor. And I think he’s just in a good position to be able to do that better than ever really.”

Yan Turcotte / Sphere Media / CTV

The importance of Mags and June’s friendship

The other key relationship in Mags’ life was hers with June, with the former helping the latter to open up.

“They spoke their own language, they understood each other in that way,” reflects Leboeuf. “They understood the boundaries or there’s sometimes no boundaries, that June was able to accept that from Mags and they had this way to give each other space and to really target, especially for June, this wound that she has. And I think Mags had a space to touch that. Their last conversation was about telling her you are loved and I’m here for you, but know that you are loved. And I thought that was nice. It was nice to see that female friendship on screen, too.”

According to Issa, she and Leboeuf are good friends offscreen. “We have a really strong relationship. We’re constantly kind of catching each other up on what’s going on and being supportive of each other through all kinds of personal life stuff. And so it was really easy, I think, to bring that level of love and appreciation to our characters. I think we instantly felt that way about each other,” she shares. That’s different from the characters, who took time to warm up to each other.

“I love the fact that what I see on screen, the way that Joe wrote it, the way that we played it, really mimics my personal perception of a strong, healthy friendship between two people, which is you push other to be accountable for yourself,” Issa continues. “You look out for each other, you call each other out on your BS. You are there and you’re sensitive to each other’s needs, but ultimately you’re there to ensure that the other person, this person you call your friend is on track to who they say they want to be and what is they say they want for themselves. And I think that Mags and June did that really nicely. And as a result of that and as a result of their care and respect and love for each other, they took on a lot of each other’s characteristics in a way that they needed to to grow and evolve and become broader people.”

When Transplant almost killed off Mags

Mags almost didn’t make it to the final season, creator Joseph Kay reveals.

“We talked about doing it earlier, the end of Season 3. We explored it fully because as soon as we introduced this idea of her chronic heart problems, it was the plan. Hamza knew it was the plan. The plans can always change, as we all know. So we did talk about doing it earlier, but then decided that waiting for the last third of the last season was the right time to do it,” he says. “You had to present a crisis in his life, can’t be his sister. That would be cruel on a whole other level. So we would never, ever, ever have done that. And that really leaves her as the best worst choice.”

What did you think of Mags’ death? Let us know in the comments section below.

Transplant, Thursdays, 8/7c, NBC