'This Is Us' Finale: Randall & Kevin's Tension Reaches a Breaking Point in 'Strangers: Part Two' (RECAP)

Meaghan Darwish
This Is Us Season 4 finale
Spoiler Alert Ron Batzdorff/NBC

[Warning: The below contains MAJOR spoilers for Season 4, Episode 18 of This Is Us, "Strangers: Part Two."]

This Is Us gave fans plenty to ponder as it closed out its fourth season with the promise of more to come — in two more seasons, which have already been ordered by NBC.

Below, we're breaking down all of the drama taking place in the present, past and future along with the return of some fan favorite characters. Beware of major spoilers ahead, and make sure to watch before reading on.

'This Is Us': Will the Clinical Trial Work? Why It May Not Help Rebecca

'This Is Us': Will the Clinical Trial Work? Why It May Not Help Rebecca

Rebecca's future has been teased various times throughout Season 4, could those flash forwards hold answers?

The Big 3's First Birthday

This Is Us Dr. K

(Credit: Mitchell Haddad/NBC)

In the past, we see Rebecca (Mandy Moore) and Jack (Milo Ventimiglia) recreate the terrible towel scene from the series premiere —only this time, it's celebrating Jack's 37th birthday and the Big 3's first. Despite the happy occasion, which includes a three-layer cake — a Pearson tradition based on future events — Rebecca can't stop herself from walking away and crying. Looking after her, Jack finds Rebecca in their room and she's upset because she's thinking about Kyle — the baby they lost during delivery.

Jack admits that he thinks about the baby too, and while they're unsure of the antidote for making this pain disappear, he asks if she's up for a ride. They end up seeking answers from their physician, the beloved Dr. K (returning guest star Gerald McRaney). Arriving with the Big 3 in tow, the Pearsons are welcomed into his office.

As per usual, the doc has some sage words of wisdom to share after deducing he's already provided the now famous advice of how Jack took "the sourest lemon that life had to offer and turned it into something resembling lemonade." Now, Dr. K recounts how he used to sing the song "Blue Skies" to his wife's pregnant belly when their first child was on the way.

After they'd lost the baby during birth, the continued to listen to the song and it made them sad, but he then goes on to reveal that 25 years later he danced with his daughter to the song at her wedding. The lesson to be gained? We have to let sadness and happiness co-exist.  When the Pearsons depart, we then see him pick up a photo on his desk as he begins singing the tune he mentioned.

The Pearson's Present in Chaos

This Is Us Randall Kevin

(Credit: Ron Batzdorff/NBC)

In the present timeline, plenty of action took place, including the introduction of new characters. Kicking off with the preparation for baby Jack's first birthday, we see Rebecca recreating the three-layer cake seen in the past for her grandson. While she helps Kate (Chrissy Metz), Rebecca learns that Toby (Chris Sullivan) and Kate have a surprise, but no one is excited about it.

As Kevin (Justin Hartley)  is heading into an AA meeting he receives a call from Uncle Nicky (Griffin Dunne) who sent sneakers for baby Jack in the mail. The pair joke over the phone before cutting the call. Meanwhile, Randall (Sterling K. Brown) and Beth (Susan Kelechi Watson) prep their family's trip to California, getting their girls out the door, among which is Deja (Lyric Ross) who is sad to leave her boyfriend Malik (Asante Blackk). Setting the alarm, Beth calls out Randall's convincing of Rebecca to do the clinical trial, and it's clear she's skeptical of the whole venture but she doesn't push it further. Eventually the group departs from Philly and we later see them arrive at the party for baby Jack.

'This Is Us': Are You Team Kevin or Team Randall? (POLL)

'This Is Us': Are You Team Kevin or Team Randall? (POLL)

The line has been drawn in the sand between the Pearson brothers.

In the midst of the party, Kevin interrupts Randall and Beth's alone time, asking to speak with his brother, which signals her cue to leave. Broaching the topic of Rebecca, he says he knows how badly Randall wanted her to do the trial, but that he thinks this is best for their mom to choose her own path, unaware that Randall's already changed her decision. Randall then takes the opportunity to congratulate Kevin on being a year sober, which he's grateful for.

Next we see Randall approach Rebecca and she takes this as an opportunity to reveal to the family that she's decided to do the medical trail in St. Louis and that her and Miguel (Jon Huertas) will be moving there for the duration. She masks the decision as a plan made by her and Miguel, not giving Randall's involvement away. It's clear that Kate and Kevin are suspicious of the change in opinion though.

This Is Us Kate Toby

(Credit: Ron Batzdorff/NBC)

Later we see the Big 3 congregate to talk about Rebecca's decision and Randall plays it off saying that she probably sees it as an investment in her future. Taking this opportunity to bow out, Toby grabs Kate's attention and they, along with Jack, head out for their secret surprise no one cared to ask about. And Kevin is relentless on Randall, continuing to question Rebecca's motives for choosing the clinical trial.

We eventually learn Kate and Toby's surprise was visiting the NICU where baby Jack had been for his first few weeks. There, they posted his photo on a special bulletin board that celebrated the progress of former patients. It's here that Toby brings up the idea of giving Jack a sibling, and when Kate's hesitant he points out that the Pearsons have had a good track record with adoption.

'This Is Us' Mandy Moore & Milo Ventimiglia Open Up About Their TV Marriage (VIDEO)

'This Is Us' Mandy Moore & Milo Ventimiglia Open Up About Their TV Marriage (VIDEO)

The stars of NBC's biggest hit answered our burning Season 4 questions heading into the March 24 finale.

Suggesting that they think about it, Toby brings it up again when they've left the hospital parking lot, asking his wife if she feels any different about the idea. When she admits she's into the possibility of adoption, we see them looking through listings on their phone from the car.

Meanwhile, we're introduced to a man on a ranch who is new to the show. While his place in the Pearson timeline isn't clear at first, it's later revealed he's from the present. When a little girl joins him, it's obvious from their conversation that she's his daughter. When he tells her he's having a hard time with the horse, she says that he can't give up.

This Is Us Rebecca Miguel

(Credit: Mitchell Haddad/NBC)

He takes this advice to work where we see him in an office looking at a photo of the girl on his desk. He then enters an exam room where Madison (Caitlin Thompson) is sitting on the table pregnant. Upset, she worries that the father — who is Kevin — was after an epic love story, and how "there's no way he'd want this." The doctor then tells her she can't know without trying.

Back at Kate's house, where the remnants of the party are wrapping up, Kevin talks with Rebecca who mentions her decision was made as an investment in her future. Seeing the correlation between her and Randall's words, Kevin knows who to blame for the clinical trial choice. Beth notices what's about to happen and whisks Rebecca away, leaving the house with her girls for some sightseeing.

Where's Kate in 'This Is Us' Flash-Forwards? 3 Theories for Her Absence

Where's Kate in 'This Is Us' Flash-Forwards? 3 Theories for Her Absence

The Pearson has been notably missing from future timelines.

This is when the confrontation begins with Kevin asking what Randall did to change Rebecca's mind, "I did whatever I needed to do," he admits. Kevin is angry that Randall wouldn't let Rebecca side with him on this, but Randall counters that everyone will regret it if Rebecca doesn't do the trial.

Just in time, Madison arrives at the door and Kevin tells her just how bad her timing is. Randall then bolts, leaving the pair alone for her to reveal the news about her pregnancy. She tells him that she doesn't expect anything, but considering how difficult it should be for her to get pregnant, she has no plans to give the chance up even if she's going to do it alone. "I think I might pass out," he tells her.

This Is Us Kevin Randall

(Credit: Ron Batzdorff/NBC)

Taking a second to breathe, he steps outside only to be approached by Randall who claims he's selfish because he wants Rebecca around, that he doesn't actually care about their mother. Kevin comes back at him, saying that if he was there the night Jack died, he wouldn't have let their dad back inside the house to which Randall says Kevin wasn't there and Jack died ashamed of him.

If this seemed like the lowest moment ... it wasn't. That came moments later when Kevin told Randall that the worst thing to happen was the day Rebecca and Jack took him home with them from the hospital. For viewers looking for the reason behind the brothers' estrangement, it's pretty easy to see this as the cause as they go off their separate ways.

Why 'This Is Us' Didn't Show Randall's Therapist Until the End

Why 'This Is Us' Didn't Show Randall's Therapist Until the End

Can 'Better Things' Pamela Adlon help Randall?

Meanwhile we see montages of other characters in the present as Cassidy (Jennifer Morrison) picks up Nicky for a meeting and Sophie (Alexandra Breckenridge) sees a cologne ad featuring Kevin on the subway marker and lets out a laugh. The present concludes with Kevin going back into Kate's house where he says, "I'm so sick of chasing ghosts" before adding "I'm all in." What is he all in on to be exact? Twins, it would seem, as Madison tells him that's what they're expecting.

Future Pearsons

This Is Us The Big 3

(Credit: Ron Batzdorff/NBC)

As per This Is Us twists, the season finale included plenty of flash forwards as the episode opened with Kate and Toby's adult son Jack (Blake Stadnik) singing to his pregnant wife Lucy (Auden Thornton). When she goes into labor they head to the hospital where they discuss baby names and wonder why they chose to not learn the baby's sex beforehand. A nurse accidentally reveals that it's a girl, allowing them to marvel in that detail until she gives birth.

Meanwhile we're introduced to another new character — a young woman working in an art gallery who is barraged by her coworker with questions about a fling she had with a possible movie star . This detail is placed in the episode almost as a way to throw off viewers who may question if she was Kevin's baby mamma, but she's actually someone completely different.

6 'This Is Us' Series Callbacks From 'The Cabin' Episode

6 'This Is Us' Series Callbacks From 'The Cabin' Episode

The latest episode included more than a few nods to past episodes.

Asking for the coworker to cover, she rushes out, late for what he thinks is a date, but is actually the birth of Jack and Lucy's baby because she's his sister. This hints that Kate and Toby's adoption idea does succeed because we're introduced to another member of the Pearson family. Once there, we learn that Lucy and Jack have decided to name their new daughter Hope, and the siblings share a sweet glance.

As for the flash forwards fans have been seeing for seasons now, in the cabin, we see Kevin join Randall and Nicky by Rebecca's bedside as Kevin's twins also enter the room — a boy and a girl. And for those who have almost lost hope in Kevin and Randall, we see Kevin put a hand on Randall's shoulder and the screen fades to black.

What will be in store next season? Plenty of drama, we're sure, but rest assured, more stories with the Pearsons are on the way.

This Is Us, Season 5, TBA, NBC