"There was so much happening that it was really wonderful to see that the story was written that they were weren't going to let this really, really hard, difficult hurdle break them and that they have conceived before so there's hope they could conceive again if and when they're ready," Metz told E! News. "Just like life, we don't know what it's going to hand us, but it's not what happens to us but how you react to it. That's the real beauty of Kate and Toby's relationship."
Aside from her relationship with Toby, Kate's strained relationship with her mom Rebecca (Mandy Moore ) also took a major turn, with Kate finally leaning on her mother after always keeping her at arm's distance. (The backstory also provided a lot of insight into their relationship and Kate's insecurities about never measuring up to her mother.)
"It's like, wow, for the first time she's being vulnerable in a way we've never seen Kate as a woman in front of anybody, much less her mom. I think so much was said and forgiven and moving forward, realizing that as an adult, it's different understanding your parent as a kid and then as an adult you're like, oh, they're just trying to figure this out too. They're just human, they just happen to be older and we call then mom and dad."
She continued, "It's such a beautiful unveiling of that real unconditional love that family has for each other. It was really great, it's always great to work with Mandy. I just have so much respect for her, so I definitely look up to her. Of course not as a motherly figure, but it was wonderful to shoot, just to have that exposed."
Given all the emotional scenes in the episode, Metz said it was one of the most difficult episodes she's had to shoot so far on This Is Us.
"It was challenging because you don't get to just take one take and then you're done. You sit in that space all day or all week. I think we worked 12 days out of 15 days or something, and at the end of the day, I don't want to talk to anybody!" she said. "I just want to cry a little bit more, take a shower and go to bed...I don't want to say there's responsibility, but I wanted to do it justice. I want it to be authentic and you gotta live that in some capacity to do so."
As for what's ahead in the final installment of the trilogy, centering on Randall (Sterling K. Brown), Metz said prepare to see a lot of exploration of the various family dynamics within the Pearsons.
"There's what's going on with Kevin and how does that affect Kate and their relationship and the family as a whole because now we're starting to see a pattern," Metz said. "Kate has an addiction to food. Now Kevin is filling a void with pills…and Jack was an alcoholic. What does this mean for the family and how does Randall internalize that? There's a lot of discovery about the family dynamics coming up which is going to be really amazing."
This Is Us airs Tuesdays at 9 p.m. on NBC.
(E! and NBC are both part of the NBCUniversal family.)