The Big Three's 40th birthday is fast approaching and everyone heads to the cabin for the milestone, except Randall; Flashbacks show the immediate lead ups to the Big Three's births and Randall's biological mother.

With the Big Three's 40th birthday now here, flashbacks in the immediate lead up to their births continue, with Randall's not as straightforward as it appears; Kevin and Madison make a decision about their future.

Kevin and Madison navigate their engagement as Kate and Toby take a big step in their adoption journey. Jack and Rebecca brace for puberty.

Malik shadows Randall at work. Kevin struggles to connect with his new movie director. Jack and Rebecca struggle to sleep train their babies.

Kate confronts her past. Randall's viral fame leans to an unexpected discovery. Kevin debates his future.

Randall uncovers new truths about his past.

Kevin embarks on a stressful road trip; Jack and young Kevin go to a football training camp.

The Pearsons navigate huge family milestones together but from a distance.

A series of car rides propels the Pearsons towards new stages of their lives.

Beth navigates qualms with her mother; Kevin and Kate bring their families together for dinner.

Kevin and Madison get an unexpected guest.

Jack and Miguel bond. Kevin and Madison navigate challenges. Randall seeks out a new kind of support network.

Kevin visits Randall in Philadelphia.

Beth navigates her career path. Kate and Toby face unexpected issues. A run-in with someone from his past gives Kevin pause.

Kevin and Madison partake in their respective bachelor and bachelorette parties.

The family gathers for Kevin and Madison's wedding.