This Is Us star Mandy Moore breaks down Rebecca's apology, final season wish list

Moms are always there to remind us that "everything's going to be all right," and that was Rebecca's mantra on the season 5 finale of This Is Us.

Kevin (Justin Hartley) and Madison's (Caitlin Thompson) wedding day finally arrived. While Kevin groomzilla'd out over every tiny detail, Rebecca (Mandy Moore) pursued another conversation she'd been longing to have: talking to Randall (Sterling K. Brown) about his trip to New Orleans and what he discovered about his birth mother, Laurel (Jennifer C. Holmes).

Randall was reluctant to get into such a thorny subject on his brother's wedding day, but when some downtime left him cornered, he acquiesced and began showing Rebecca pictures. But she teared up after only two photos.

Later, though, she found Randall and issued the mother of all apologies, admitting her shame and guilt over keeping the things she knew about William (Ron Cephas Jones) and Laurel from him. But not only that — her guilt over never giving him an opening as a child, a teenager, or an adult to discuss the complicated feelings he had being a Black child raised by a white family.

"That conversation with Randall was one she needed to have for 40 years, and there was no time like the present," Moore told EW editor in chief Mary Margaret at a season 5 finale panel Tuesday night in Pasadena, Calif. "She really feels the burden of the clock ticking and not knowing how things are going to unfold in the foreseeable future, so it was really important for her to have the conversation to take full ownership and responsibility for the choice she made, but it wasn't an easy conversation."

Randall was quick to forgive, taking Rebecca into an embrace and subtly reassuring her of their bond by amending her description of Laurel as his "mother" to "birth mother."

While Randall and Rebecca were stronger than ever, other Pearson family units broke down. Madison called off the wedding, realizing she couldn't marry a man who wasn't in love with her after Kevin just couldn't find the words. Kate (Chrissy Metz) and Toby (Chris Sullivan) seemed to patch up their rocky marriage after coming to an understanding over who would be a stay-at-home parent (answer: neither), but a five-year flash-forward revealed that the reconciliation would be short-lived enough to find Kate marrying her music teacher boss, Phillip (Chris Geere).

For the time being, though, Rebecca was there to reassure her kids all would be well — even if she could no longer readily imagine Jack (Milo Ventimiglia) and how he would react to their current circumstances.

EW caught up with Moore at the finale event to discuss that long-awaited mea culpa, Rebecca's impending sense of borrowed time, and the forthcoming Big Three house.

ENTERTAINMENT WEEKLY: It feels like we've been working up to this gut-wrenching apology for awhile. How did you approach that scene, and where Rebecca was coming from? Was that an essential step in her journey of healing as she tries to find some resolution with the ticking clock of her illness?

MANDY MOORE: The clock is ticking. I do think it is an essential part of her healing. It was a long time coming. She just was avoiding having the conversation, avoiding the subject matter, but also being unbelievably curious what his trip was like to New Orleans, and she knew that would therefore open a can of worms. With so much of this show, there's this collective history you bring along with you as the actor, as the human, and it makes it a little bit easier of, "Oh I have five seasons to lean on of this relationship with Sterling, of this relationship between Rebecca and Randall," and all of that is brought to the table in those particular moments. Because it's just so heavy. I can't imagine what it's like to have had 40 years of this burden and this secret, so all of that's easy to bring with you.

In this mini flash-forward, we see almost the entire family, except Rebecca. How much worse might she be mentally by this time? Or is her absence evidence that's she just still team Toby?

[Laughs] Rebecca is there. We didn't see her, but perhaps we will still. Perhaps there will be a bigger picture to lean into that particular time, but you will see her. She is obviously still around.

Rebecca says she's increasingly struggling to picture Jack at family events. She tips that it might be a symptom of her disease. How much do you think that's true, or is it just a product of she's lived as much life without Jack as she did with him at this point?

It's a little bit of both, but probably more the latter. With anybody who's lost somebody, it's strange as time goes on, the edges start to get a little bit fuzzy. It's ultimately a devastating concept for her that in these big, huge life moments she's not able to imagine him around as much.

Rebecca asks Kevin to build her a house. What is that house going to mean to her and the Pearsons as a family base?

Well, we've seen the house. It's pretty stellar. It's just the culmination of a dream, of plans being fully realized. Maybe this idea that she had for herself of growing old with Jack. At least there's some semblance of that dream that will get to be lived out to some degree, and she's excited about that.

You're going into your final season, and creator Dan Fogelman said it will be very ambitious for you particularly. What are you excited for? And what's one thing you hope to accomplish that you haven't done yet on the show?

I'm scared. I think people are really curious about Rebecca and Miguel, so Jon Huertas and I have been pitching Dan on, "Can we just have a full-fledged Rebecca-Miguel wedding? Can we see what the wedding is in Puerto Rico? Are they doing shots with each other?" I'm really curious about that in a fun sense. But I know that there's going to be a lot of emotions just across the board as the disease progresses, watching her and her family and Miguel as her caregiver — all of that is going to be tremendously difficult and emotional and all the things.

I'm excited, which sounds so strange to say, but I'm excited about the challenge of what that's going to be and what that's going to look like, but also doing our best to really honor that particular story line. It really means a lot to me, and I know it means a lot to a lot of people who are living this life, either with a parent or spouse or family member, so I want to make sure we get it right.

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