Warning: SPOILERS for Star Trek: Lower Decks Season 4 Finale - "Old Friends, New Planets"

Summary

• "Star Trek: Lower Decks" season 4 finale delivers an explosive and thrilling conclusion, as Mariner saves the galaxy from Locarno's plan to establish a new power.
• Mariner reaffirms her belief in Starfleet, contrasting with Locarno's resentment and lack of responsibility for his actions.
• Tendi leaves Starfleet to return to the Orion Syndicate, raising questions about her future and the exploration of Orion culture in "Lower Decks" season 5.

Star Trek: Lower Decks season 4 ended with a thrilling and explosive finale where Lieutenant Beckett Mariner (Tawny Newsome) saved the galaxy from disgraced ex-Starfleet Academy Cadet Nicholas Locarno (Robert Duncan McNeill), but at the cost of Lieutenant D'Vana Tendi (Noël Wells) leaving Starfleet and returning to Orion. Locarno beamed Mariner aboard his starship, Nova One, revealing that he was the villain attacking non-Federation ships and stranding their command crews on the planet Sherbal V throughout Lower Decks season 4.

Locarno's plan was to establish himself as a new power in the galaxy. Thanks to the various crews of alien Lower Deckers who mutinied against their superior officers, Locarno assembled an armada he called Nova Fleet, named after Nova Squadron, the failed elite group of Starfleet Academy Cadets Nicholas Locarno led in the Star Trek: The Next Generation season 5 episode, "The First Duty." Locarno's ace-in-the-hole was a Ferengi black market Genesis Device he planned to use to blackmail the United Federation of Planets. But Mariner stole the device and escaped on a stolen Starfleet ship, although she was trapped in the Detrion System by a Trynar Shield. Captain Carol Freeman (Dawnn Lewis) and the USS Cerritos successfully rescued Mariner, with explosive results that created a new planet.

Star Trek: Lower Decks' Genesis Device Creates A New Locarno Planet

A Great Star Trek II: The Wrath Of Khan Homage

Caught inside a nebula with Locarno, Mariner activated the Ferengi Genesis Device (which she nicknamed "G.D.") to keep Locarno from using it. Locarno tried to kill Mariner with a phaser, but Beckett was beamed onto Freeman's Captain's Yacht in the nick of time. However, Locarno refused to surrender and come with Mariner as the Captain's Yacht fled to safety. Instead, Locarno tried to disable the Genesis Device, but the Ferengi's paywall prevented it. Locarno was killed when the Genesis Device exploded, and his molecules were bonded with the new Genesis Planet that formed, which Starfleet named Locarno.

These jokes pay off the visit to Ferenginar in Lower Decks season 4, and the introduction of Freeman's Captain's Yacht in Lower Decks season 1.

Star Trek: Lower Decks season 4's finale was the franchise's latest homage to Star Trek II: The Wrath of Khan, but it was also the best one. For all of Locarno's lofty talk of Lower Deckers turning the tables on their superior officers, he was just a man like Khan (Richardo Montalban) out for revenge. Happily, none of the Cerritos' crew sacrificed their lives to stop Locarno, so there wasn't a spin on Spock's (Leonard Nimoy) death like there was with Data (Brent Spiner) in Star Trek: Nemesis or Captain James T. Kirk (Chris Pine) in Star Trek Into Darkness. What will become of the Locarno Genesis Planet will hopefully be addressed in Star Trek: Lower Decks season 5.

Mariner Believes In Starfleet, Unlike Nick Locarno

Mariner dealt with her "pretty heavy stuff."

Star Trek: Lower Decks season 4 saw Beckett Mariner cope (self-destructively) with being promoted to Lieutenant, junior grade, which brought back her feelings of dread tied to the death of her friend from Starfleet Academy, Ensign Sito Jaxa (Shannon Fill). Incredibly, Lower Decks season 4's finale opened with a flashback to before Star Trek: The Next Generation's "The First Duty" in 2368, which showed a young and enthusiastic Cadet Mariner doting on Sito and Nova Squadron, including Wesley Crusher (Wil Wheaton) and Joshua Albert, who is seen alive for the first time since he was tragically killed in a prohibited flight accident before "The First Duty." Sito's death defines Mariner's fear of being promoted and being forced to send others to their deaths, which explains why Beckett only wants to be a Starfleet Ensign.

Facing Nick Locarno, who himself was defined by being expelled from Starfleet Academy because of his own ego, Mariner reaffirmed her own belief in Starfleet. Locarno never forgave Starfleet for how he was treated, and he never really accepted responsibility for his actions in getting Joshua Albert killed and covering it up. For her part, Mariner fully understands that Starfleet isn't perfect and makes many mistakes, but that it is also inherently good, and Ensign Sito gave her life to protect Starfleet. Mariner is also inherently good since she never considered Locarno's offer to him and risked her life to keep the Genesis Device ("a planetary murder machine") out of Locarno's grasp. Mariner also urged Nick to come with her instead of dying in a Genesis explosion. Hopefully, Mariner now accepts her new role as Lieutenant on the USS Cerritos and can apply her innumerable talents to improving Starfleet instead of constantly rebelling against it - although she wouldn't really be Beckett Mariner if she did.

Tendi Leaves Starfleet And Returns To The Orions - Will She Be Back?

The Mistress of the Winter Constellations returns to the Orion Syndicate

Lt. D'Vana Tendi offered a solution after Captain Carol Freeman decided to commit an insurrection against Starfleet to save Mariner by asking her sister, D'Erika Tendi (Ariel Winter), for help. After a Star Trek: The Original Series "Gamesmasters of Triskelion"-like trial-by-combat that Dr. Migleemoo (Paul F. Tompkins) lost for the Cerritos' crew, Tendi offered to return to the Orion Syndicate as the Mistress of the Winter Constellations rather than turn over the USS Cerritos to D'Erika as they previously wagered. Being an Orion, D'Erika bamboozled Tendi and Captain Freeman by loaning them an inoperable battleship, but the Cerritos ingeniously threw the battleship at Locarno's Trynar Shield to bring it down.

The Cerritos throwing the battleship is Star Trek: Lower Decks' ode to Captain Will Riker (Jonathan Frakes) using the USS Titan-A to throw an asteroid at the Shrike in Star Trek: Picard season 3.

Following the successful defeat of Locarno and the rescue of Mariner, Tendi had to make good on her promise to return to Orion since D'Erika "didn't waste any time" demanding her sister become the Mistress of the Winter Constellations once more. Interestingly, Tendi's Lower Decker friends seemed quite confident Tendi would be back in Starfleet, although Lt. Samathan Rutherford (Eugene Cordero) has very mixed emotions he hasn't dealt with about D'Vana after they awkwardly posed as newlyweds on Ferenginar in Star Trek: Lower Decks season 4, episode 6 - "Parth Ferengi's Heart Place." With Tendi gone for however long, the Lower Deckers are back to four : Beckett Mariner, Sam Rutherford, Brad Boimler (Jack Quaid), and T'Lyn (Gabrielle Ruiz).

Meanwhile, Starfleet is pleased with Captain Freeman for opening up diplomatic relations with the Orions for the first time ever in spite of the loss of Lt. Tendi. Thanks To Tendi and her powerful crime family, Star Trek: Lower Decks has provided the most thorough exploration of the Orion culture since the green-skinned space pirates were introduced in Star Trek: The Original Series. With Tendi back with the Orion Syndicate, this will continue to be a staple of Star Trek: Lower Decks in season 5.

Captain Boimler Commands The USS Cerritos

A hint of things to come for Lieutenant Brad Boimler?

Acting Captain Brad Boimler (with a deeper Captain's voice) commanded the USS Cerritos when they threw the Orion battleship to bring down the Trynar Shield, allowing Captain Carol Freeman into the Detrion System to rescue Mariner. Boimler was understandably proud that Commander Jack Ransom (Jerry O'Connell) was "very happy" with his "Captain-ing", and Bradward did seem right at home and confident in the Cerritos' center seat. Lt. T'Lyn sitting at Boimler's right also looked appropriate as T'Lyn and Boimler give off Spock and Captain James T. Kirk (William Shatner) vibes when they work together.

Boimler seems destined to achieve his dream of becoming a starship captain one day. Star Trek: Strange New Worlds' crossover with Star Trek: Lower Decks planted the seed for future Captain Boimler in his encounter with the USS Enterprise's Captain Christopher Pike (Anson Mount). Boimler saved the USS Voyager in Lower Decks season 4's premiere, "Twovix," earning his promotion to Lieutenant junior grade, and he commanded his first away mission in Lower Decks season 4, episode 2, "I Have No Bones, Yet I Must Flee," although Bradward was, briefly, the only casualty. Of course, Boimler has to stay a Lower Decker in Star Trek: Lower Decks, but it's safe to assume Captain Boimler will command his own starship at some point in Star Trek's future.

T'Lyn Is Staying On The Cerritos

And T'Lyn wants to be "science besties" with Tendi.

Lieutenant T'Lyn chose to ignore a call from her Vulcan Captain, Sokel, and decided to remain in Starfleet aboard the USS Cerritos. This concluded T'Lyn's arc where she originally hoped spending some time in Starfleet would be a gateway back to the Vulcan fleet until T'Lyn realized she was not "broken" as her superiors believed her to be. Aboard the Cerritos, especially with Mariner, Boimler, and Tendi, T'Lyn has found genuine friendships with the very loud and illogical humans and Orion. Plus T'Lyn finally gave the desperate Tendi what she yearned for by agreeing to be "science besties," although D'Vana had to leave the Cerritos immediately after. The addition of the wry, unflappable, and unrelentingly funny Star Trek: Lower Decks has been a slam-dunk, and the Vulcan staying on the Cerritos for season 5 is great news.

What Season 4's Ending Means For Star Trek: Lower Decks Season 5

Star Trek: Lower Decks season 5 premieres in 2024 on Paramount+.

Star Trek: Lower Decks is returning for season 5 on Paramount+, and the animated comedy's usual late summer/early fall release date will likely be the same in 2024. Lower Decks season 4 actually concluded a couple of long-running story arcs, such as the show's malevolent A.I. villains. Badgey (Jack McBrayer) ascended to become a higher life form alongside Star Trek: Lower Decks' weird koala, while Peanut Hamper (Kether Donohue) and AGIMUS (Jeffrey Combs) seem to be reformed evil computers. Mariner has faced her issues with being promoted and reaffirmed her faith in Starfleet while Boimler is on his way up the ranks toward his Starfleet dream of becoming Captain. Lower Decks season 4 ends with a relatively clean slate for Lower Decks season 5, save for how to get Tendi back to the Cerritos.

One thing Star Trek: Lower Decks season 4 didn't address was the "death" of Brad's clone William Boimler, who defected to Section 31 in season 3.

Star Trek: Lower Decks season 5 has an important role to play as one of only two Star Trek series confirmed to stream in 2024 on Paramount+, the other being the final season of Star Trek: Discovery. The Star Trek: Section 31 movie starring Academy Award-winner Michelle Yeoh is the only other known project with a shot at streaming on Paramount+ in 2024 since Star Trek: Prodigy season 2 found a new home on Netflix, which will stream all 20 season 2 episodes next year. With its setting and loving exploration of the late 24th century Star Trek: The Next Generation era, Star Trek: Lower Decks will essentially become the centerpiece of Star Trek on Paramount+ in 2024 after Discovery ends, and this will hopefully garner series creator Mike McMahan's animated comedy more seasons so that he can complete his grand vision for Lower Decks.

Star Trek: Lower Decks season 4 is available to stream on Paramount+.