It’s baby Jack’s first birthday on This Is Us, and with the whole family being together as well as the episode being the season finale, there’s bound to be drama. 

Last week’s episode ended with Randall (Sterling K. Brown) begging Rebecca (Mandy Moore) to do the drug trial in St. Louis, and Rebecca finally caving and agreeing to go. 

This week, the episode begins by introducing two new characters and one familiar face: Jack (Blake Stadnik) and his wife, Lucy (Auden Thornton), who is going into labor, a woman who works at an art gallery and a man training a horse with his daughter.

Back with the regular cast, the whole family goes out to California for Jack’s first birthday, hosted by Kate (Chrissy Metz) and Toby (Chris Sullivan). Rebecca makes the announcement to the family that she’s doing the drug trial in St. Louis, and though Kevin (Justin Hartley) and Kate are skeptical about Rebecca’s sudden change of heart, they know that if it’s what she wants, she should do it.

In the past, Rebecca and Jack (Milo Ventimiglia) go to see Dr. Nathan Katowski (Gerald McRaney) after Rebecca finds herself having a hard time forgetting the triplet they lost at birth. He gives them great advice, as per usual, and it’s a great way for the audience to see a character they haven’t seen in a while. 

Back in the present, everything seems to be going well with the Big Three. They’re laughing, happy, teasing each other and generally enjoying life. It’s one of the most serene moments in the season. Toby, however, is forced to interrupt the moment as he takes Kate on a super secret mission. 

The couple travels to the NICU, and Toby tells Kate he thinks they should adopt a child for Jack to have a sibling. After much debate, they both feel that it’s the right thing to do and begin looking for a child. It is soon revealed that the adult female character who was newly introduced is Kate and Toby’s adopted daughter, who is rushing to the hospital to be with Jack and Lucy as they deliver their baby.

All that’s left is the answer to who the man with the horse is, which is quickly confirmed to be Madison’s (Caitlin Thompson) doctor. However, her visit has nothing to do with her eating disorder: Madison is pregnant with Kevin’s baby. 

Meanwhile, Kevin discovers that Randall greatly pressured Rebecca into doing the drug trial, and that it wasn’t her choice. The two get into one of the most heated arguments This Is Us has ever seen, with Kevin telling Randall that he failed to save their father, Randall telling Kevin that Jack died ashamed of Kevin because he’s selfish and will never be as good as Randall. The argument ends with Kevin virtually ending whatever brotherly bond was left between the two by saying: 

“You know, I used to think the worst thing that happened to me was the day dad died,” Kevin said. “It’s the day they brought you home. Hand to God, Randall, the worst thing that ever happened to me was the day they brought you home.” 

And with that, Randall leaves. In the middle of the argument, Madison shows up to tell Kevin about the baby. Kevin is stunned but tells Madison that he’s going to do whatever he can to support her and their child. 

This is when it fast forwards to Rebecca’s death bed, where the Big Three have aged a number of years. Nicky is there, with a wedding ring on his hand, and Randall stands by Rebecca when Kevin enters. The voiceover has Madison telling Kevin that they’re going to be having twins, not just one baby, and two young children run in to hug future Kevin. 

At the same time, Jack has his baby, and they name her Hope. 

Virtually every character comes back in this episode. Malik (Asante Blackk), Cassidy (Jennifer Morrison), Sophie (Alexandra Breckenridge), Nicky and Dr. Katowski are just a few of the names of returning characters. 

The entire episode is really heartbreaking and absorbing, setting up new additions and plotlines that will surely make season five amazing.