The 'This Is Us' Season 4 Finale Promo Promises A Serious Gut Punch

It's been a long six months since This Is Us Season 4 premiered back in September of 2019. Since then, the world has changed a lot for the Pearson clan. Baby Jack was confirmed to be blind, Rebecca has been diagnosed with the early stages of Alzheimer's, and Randall finally went to therapy, among other significant developments. But with one episode to go before the show goes on summer hiatus, there's one more giant shift to come. The This Is Us Season 4 finale promo may sing about "Blue Skies," but the dark clouds are impossible to ignore. Warning: Spoilers for This Is Us Season 4 follow.

The penultimate episode of Season 4 ended on a discordant note. After Randall insisted he would not use his resentment of his mother hiding William's existence for all those years, he failed to hold himself to it. His late-night phone call to the west coast was a masterclass in emotional manipulation. "I've been a good son," he exhorted. "I've never asked for anything... I've never held things against you." Rebecca, understanding Randall was evoking the ghost of William, finally bent to his pleas. She would go to St. Louis; she would start the clinical trial, and she would do as he asked.

As fans know, by the time Season 5 premieres (hopefully this fall), Randall's decision to force Rebecca to do what he wants will blow up the family.

The finale episode is entitled "Strangers Part 2," forming a bookend to the Season 4 premiere, "Strangers." As for the synopsis, it explains why the family is together in California for the final episode.

The Pearsons gather to celebrate Baby Jack's first birthday.

From the looks of it, Baby Jack's first birthday will also echo up and down the timeline. In the past, there's the triplets' first birthday, bringing back a guest appearance from Dr. K; in the far future, there's the birth of Jack's son-to-be, bringing the Pearson clan story to yet another generation.

And that's only the tip of the iceberg. As executive producer Elizabeth Berger told Entertainment Weekly: "We’re in a lot of timelines. We're all over the place in this one." And there will be surprises too, things viewers cannot begin to guess. Maybe there will even be strangers fans haven't met.

Fans can only buckle up for the ride, as This Is Us Season 4 rounds to the finish line.