It's the Big Three's forty-first birthday. The general plan is for the Los Angeles crowd to convene at Kate and Toby's later in the day and link then with Randall's family via video. It doesn't start as the ideal day for almost all concerned. Toby, who is necessarily in San Francisco, has a surprise for Kate in having Rebecca and Miguel take care of the kids while he has arranged for a massage for her. As appreciative as she is for Toby's gesture, Kate can't help compare this gesture to things Toby has done for her in the past. Kevin, living in Madison's garage to be close to the twins, is still trying to get his life back together following the disaster that was the movie, and figure out his new relationship with Madison beyond they co-parenting. Both Kate and Kevin can't help but think back five years ago to what was their thirty-sixth birthday in life coming full circle in some respects. Randall discovers that the man who broke into the house two years ago is in custody and is being arraigned today, Randall feeling the need to confront the person who forever changed his family's life that day. And beyond quietly being annoyed by Nicky's constant lament about his long lost love Sally, the woman he stalking on social media who he believes is her, Rebecca can't help but be more frustrated by something that happens as her mind wanders to past associations. January 28, 1986 is also shown in how that day, that of the Challenger disaster, may have foresaw how each of the Big Three, five at the time, would act/react this day.
—Huggo