Celia Rose Gooding anchors "Tomorrow's Enterprise," the Season 4 finale of "Star Trek: Strange New Worlds," now streaming on Paramount+, with a dual role that has her Lt. Uhura collaborating across time with her future self — and wearing the classic Nichelle Nichols hairdo from "Star Trek: The Original Series."

The episode, which closed the show's fourth season this week, sends Uhura back to the Enterprise from a Starfleet conference just as the crew prepares to observe a white hole, described in the episode as the counterpoint to a black hole. Uhura hears music coming from the phenomenon. Then an energy burst strikes the ship, and she hears what sounds like her own voice trying to save Scotty (Martin Quinn) from an emergency.

She is not imagining it. On the other side of the white hole, the Enterprise exists one year in the future, investigating a black hole. In that timeline, Jim Kirk (Paul Wesley) is captain, Spock (Ethan Peck) is his first officer, Pike (Anson Mount) has been promoted to admiral, and La'an (Christina Chong) is mysteriously absent. Future Uhura is in a romantic relationship with Scotty, and the two fly out on a shuttle with Ortegas (Melissa Navia), now a flight instructor at the Academy. Another energy burst hits the shuttle. Uhura transports back to the Enterprise, but Scotty dies — and she then learns that Scotty had already died a year earlier.

The two Uhuras must work together to save Scotty without disrupting the timeline, which means "TOS" Uhura has to guide her past self without revealing what the intervening year holds. "The hardest part was making them talk to each other and having 'TOS' Uhura speak on experiences that 'Strange New Worlds' Uhura hasn't had yet, and to live in that sort of liminal space," Gooding tells Variety. "As a recovering control addict, it was hard for me to live in that space and not immediately feel like I need a point in 'Strange New Worlds' Uhura's mind to leap off of and talk on."

She adds: "I crave an answer, and to be met with yourself saying, 'Hey, that's not going to help you,' it was a struggle for sure in the character. She had a hard time being told, 'You've just got to trust me. You have to trust the me, that is you.'"

Gooding also adjusted to the new look. "I was a little insecure about it at first, because I thought I looked just different, and the human brain takes a minute to understand that different doesn't mean danger," she says.

The pair plan to rebalance the timeline with a dilithium diamond, but another energy pulse swaps them between the two Enterprises. Past Uhura, now in the future, unlocks the secret of the music: an alien entity inside the hole warning the ship to stay back because a child is about to be born from it. The energy blasts, it turns out, have been "contractions." The two Uhuras successfully birth the "space baby" using specialized drones controlled from outside the ship, meeting face to face in space as the birth happens.

Shooting that sequence posed its own puzzle. "There were three different Uhuras on the call sheet at any given time," Gooding says. "It was me, my stand-in Lisa, and my stunt double Sammy. There were times in which I was having a conversation with a tennis ball on a stick, and there were times where I was having my conversation with Lisa, but we recorded my dialogue so my stand-in wasn't saying it — it was me having a conversation with my voice so the timing was right. So it was me looking at her, but hearing the voice of God, as we call it, as my voice."

Gooding calls the Uhuras' final exchange a "passing of the torch" between "Strange New Worlds" and "TOS." "'Strange New Worlds' has done all the work that we are gonna do," she says. "We have told the stories. They are written, recorded, edited. ADR is done. All we have to do is share it with the world. And I think what we have done with the series finale of 'Strange New Worlds' is tee up a series of opportunities. We could veer off and have more conversations about Kirk's captaincy, or we can launch right into the original series."

She adds: "We found a way to close this chapter for the legacy characters, but we've also been able to say goodbye to characters that only exist in 'Strange New Worlds.' And we've done it in a way that I think is really satisfying."

The finale firmly sets up the show's fifth and final season — and, on Gooding's reading, a direct handoff into "The Original Series" territory.