Star Trek: Lower Decks Brings Back a Voyager Star But Not How Fans Expect

The penultimate episode of Star Trek: Lower Decks Season 4, titled "The Inner Fight," featured the return of a Star Trek: Voyager actor reprising a role other than the one for which they're best known. SPOILERS follow for Star Trek: Lower Decks Season 4, Episode 9, "The Inner Fight." Robert Duncan McNeill is well known to Star Trek: Voyager fans for playing Tom Paris, the helmsman aboard the U.S.S. Voyager during that vessel's storied journey through the Delta Quadrant. He reprised the role in voiceover for the Star Trek: Lower Decks Season 2 episode "We'll Always Have Tom Paris," but he's reprising another character in Star Trek: Lower Decks Season 4.

McNeill voices Nick Locarno in the Star Trek: Lower Decks episode "The Inner Fight." McNeill first played Locarno in the Star Trek: The Next Generation episode "The First Duty."

Who Is Nick Locarno in Star Trek: Lower Decks?

Locarno was a Starfleet cadet who led the distinguished Nova Squadron. He convinced the squadron to attempt a banned flight maneuver for the academy's graduation ceremony, which led to the death of one of their squad mates. Locarno lied to cover up his role in the fatal accident and pressured the other Nova Squadron members, including Wesley Crusher, to back his story. Eventually, Captain Jean-Luc Picard figured out what was happening and commanded Wesley to tell the truth, lest the captain do it for him. Once Wesley broke ranks, Locarno took full responsibility for Nova Squadron performing the banned maneuver. His impassioned plea saved his surviving squad mates from facing expulsion from Starfleet Academy, as he did.

Star Trek: Voyager's creators cast McNeill as Tom Paris because they wanted a character like Locarno to undergo a redemptive arc early in the series. They thought of bringing Locarno back but ultimately felt Locarno was an irredeemable character, selfish to the core, and altered McNeill's character to become the Tom Paris that Voyager fans know and love.

What's Locarno's history with Beckett Mariner?

"The Inner Fight" reveals that Beckett Mariner knew Locarno at the academy. She was closer to Sito Jaxa, a member of Nova Squadron who appeared in "The First Duty" and returned in a later Star Trek: The Next Generation episode, "Lower Decks," which gave Star Trek: Lower Decks its name and focus. Sito is presumed dead at the end of "Lower Decks" after she, a Bajoran, is sent undercover to return a defector to Cardassian territory.

Locarno and Mariner are reunited at the end of "The Inner Fight" after Locarno abducts her. It's unclear what his plans for Mariner are.

Locarno is the Person Behind the Star Trek: Lower Decks Season 4 Mystery

At about the same time that Locarno abducts Mariner, Capt. Carol Freeman and other members of the U.S.S. Cerritos crew discover that Locarno is involved with a series of attacks on various ships throughout the galaxy using a mysterious spacecraft. ComicBook.com asked Star Trek: Lower Decks creator Mike McMahan about this season-long mystery in a previous interview.

"I wanted there to be a breadcrumb trail of something that led to a really cool season finale," McMahan said. "I think that's a fun thing, on a rewatch especially, to get to watch go down. I also really loved and wanted to get more of the storytelling we saw in 'wej Duj,' which was the three-ships episode, Season 2. Getting to do a little breadcrumb thing that replaced, if you go back and watch the first season, there were more cold open bits, standalone comedy bits that you would open the show with, and then it would get into the episode. I missed the modularity of that a little bit. We had also just experienced Season 3, where we had been building up the story of Rutherford and the Aledo and Buenamigo all season, and getting that to all work resulted in the second to last episode feeling like I had to do it instead of I wanted to do it. I still love that episode, but we needed 11 episodes that season to really resolve all of that. I told myself we would do a comic book run that filled the gap between those two episodes for Mariner being out and adventuring, but I think that I should've triggered that one episode earlier, but it's hard to navigate all that."

He continued, "Then this season, I wanted to give our characters time. Now, by just having the modularity of doing these little sketches, of seeing lower deckers and bridge crews on other alien ships and popping into them and having them be removed from the narrative, except in the Betazoids are being affected by it. You're going to see other people being affected by it, but it doesn't drive the narrative of any individual episode. It's existing within it, and it's causing changes to happen within the show, but the Cerritos isn't directly being targeted by it. That was really fun for me because then I could start an episode and be like, 'All right, we're going to see some Ferengi lower-deckers.' That was really cool. And then it gets to a place which is really like… I don't want to give anything away. I'm going to stop there."

Star Trek: Lower Decks Season 4, Episode 9, "The Inner Fight," is streaming now on Paramount+. The Star Trek: Lower Decks Season 4 finale streams Thursday on Paramount+.