SPOILER ALERT: Do not read if you have not yet watched “Strangers,” the fourth season premiere of “This Is Us.”

For three years NBC’s audience has fallen in love with (and cried over) the Pearson family on “This Is Us.” But for the majority of the fourth season premiere episode, aptly titled “Strangers,” most of those aforementioned beloved members of that family were absent.

“Strangers” did spend time with Jack (Milo Ventimiglia) and Rebecca (Mandy Moore) in the early days of their relationship when he met her parents (including new guest star Tim Matheson) for the first time). This picked up their origin story where the third season had left off and felt like “the right anchor” for the otherwise untraditional episode, says series creator Dan Fogelman.

“All of these new characters had relationships to the Big Three and less so Jack and Rebecca,” he tells Variety, “so it felt like a good thing to anchor the show with the parents. It felt like it would also be enough of a roadmap for the audience where just when you’re away from your characters too long, you get a lot of Milo and Mandy to keep us in our world while we’re also expanding it.”

That expansion included introducing new characters ranging from Jennifer Morrison’s present-day war veteran and Asante Blackk’s present day teenage father to jumping into the future to meet Kate (Chrissy Metz) and Toby’s (Chris Sullivan) grownup son Jack (Blake Stadnik).

Fogelman admits there was some anxiety around the “weird feeling” you get of not seeing the majority of the main cast for so much of the episode, but he notes that “it’s not like we’re doing an entire season of television without the Big Three in it. This is a starting point. The next three, four, five episodes are just wildly traditional episodes of the show.”

That means it will take a bit more time to dive deeper into the new characters, whose impacts will ripple out to the wider Pearson clan than first glanced in this return episode.

Initially, Morrison’s character had a chance encounter with Nicky (Griffin Dunne) when he threw a chair through the window of her Veteran Affairs support group, but Fogelman shares that it’s “fair to say” she is “on a collision course with Kevin [which] is definitely a monster part of this season.”

Similarly, Blackk’s character had a budding flirtation with Deja (Lyric Ross) in “Strangers,” but going forward in the show he — and his parents (played by Marsha Stephanie Blake and Omar Epps) — will interact with Deja’s family, too. “There’s some interesting socio-economic dynamics, and Omar and Marsha Stephanie are so exceptional, and putting them with Sterling and Susan is incredibly exciting,” Fogelman says.

In fact, Fogelman reveals, the seventh episode of the season will be a specialized episode dealing with the relationship between Blackk and Ross’ characters, which includes more insight into who he is. But, while the show is deep-diving into learning about other characters in isolated pieces, the main stories will continue to be the Pearson’ stories, Fogelman says.

“Their stories exist in relation to the Pearsons’ stories, as other characters always have,” he explains. “Our second episode back is a real chance to re-center with our family before they spread off on individual stories, but as we head to our third and beyond episodes, these characters become linked.”

The one exception is Kate and Toby’s son Jack, who has obvious connections to the rest of the Pearsons through his lineage but lives in a future timeline beyond any the show has seen before. Fogelman confirms that his “Strangers” story takes place “about 10-plus years” from the third season flash-forward that found the Pearsons gathering at an ailing Rebecca’s bedside. As an adult, Jack has a wife (Auden Thornton), a baby on the way and a successful career as a singer — and he happens to have been blind since birth.

Retinopathy is a common result when a baby is born prematurely, which Jack was. How his family reacts to raising a baby who cannot see will play a part in the present-day storyline of the fourth season of “This Is Us,” but from the glimpse at his future, he seems to have grown up up well-adjusted and successful, following in his mother and grandmother’s footsteps when it comes to their love of music, but managing to achieve much more in that arena than either of them did professionally.

“Many of our dreams, especially when they’re giant dreams, we don’t always accomplish them all in our lifetime; sometimes it takes generations to see that,” Fogelman says. “That’s always been in the fabric of our show, and with any artistic dream is so hard because it requires so much timing and so much luck and so many things you can’t control. Music was a big life force of Rebecca, and she didn’t quite get, musically, where she wanted in her life. It transitioned down to her daughter who always had just fits and starts of a budding music career. But what was really important to them — the love of music — finally came to fruition with their son and grandson. It feels like a really beautiful way to look at the world and to look at what could be perceived as a quote-unquote failure.”

“This Is Us” does plan to return to this Jack’s story later on, according to Fogelman. The show will also return to the relationship between Rebecca, her father and Jack, primarily in an episode that is “golf-focused,” Fogelman shares. “It picks up with Jack’s relationship with his soon-to-be father-in-law as he takes him to the country club to learn a sport Jack doesn’t know and is embarrassed by, and then plays generationally with how fathers teach their sons golf.” The episode will follow the three storylines of Jack and his Rebecca’s father; Jack and young Randall, as he learns from his father; and then Randall as an adult, trying to woo people politically with a round.

But, the greater focus of the first half of this season of “This Is Us” will be on the present-day story, Fogelman says, which will also provide thematic elements that tie into the future storyline with Rebecca. That part of the Pearsons story will be revisited “in the back-half of the front-half of this season,” he confirms, reiterating that that future is still “endgame” for the Pearson clan.

“We’re just kind of executing the plan we’ve always had and filling it in with colors,” he says. Although he adds that having such talented actors come to play on the show “makes you want to write more and more for those characters,” it doesn’t make him want to “deviate from our plan” or use any of the material for the new players to test the waters for potential spinoffs.

“The characters flit into your lives and become the most important people in your world are giant parts of your story,” he says. “Life is built upon the relationships you form and we’ve decided to continue expanding this world.”

“This Is Us” airs Tuesdays at 9 p.m. on NBC.