Welcome back to The Lower Decks Connection, where we curate an episode watch list of legacy Trek shows based on the latest episode of Star Trek: Lower Decks! This week’s episode saw the crew of the Cerritos visiting a very familiar location: the station Deep Space 9 herself. Fans were treated to another story featuring Colonel Kira Nerys and everyone’s favorite Ferengi businessman Quark. It was as though Star Trek: Deep Space Nine was back on our screens for an episode. 
This is not the first time that two Star Trek shows have crossed over with each other. If you’re eager for more crossovers, we’ve collected a few examples of when the legacy Star Trek shows crossed over with each other.  

Star Trek: The Next Generation - “Unification Parts 1 and 2” 

Captain Picard and Spock are held at phaser point. Data stands nearby.
"Unification Part II"

TNG had already crossed over with The Original Series before this episode – both Leonard “Bones” McCoy and Sarek had made appearances in the early seasons – but this episode was a major moment in the in-universe history of the Alpha Quadrant. Spock, ever wise, tries to bring both Vulcans and Romulans together and unify their people as they once were centuries before. It’s up to Picard and the crew of the Enterprise-D to help him as best they can. The episode beautifully concludes when it is revealed nearly two decades later in the Star Trek: Discovery episode “Unification III” that Spock’s dream was ultimately realized. 

Star Trek: The Next Generation - “Relics” 

Scotty stands next to Geordi La Forge in engineering aboard the Enterprise-D.
Star Trek: The Next Generation - "Relics"

Scotty gets to make an appearance in the TNG episode “Relics” after being missing in-universe for 75 years. Suddenly surrounded by technological advancements, Scotty contends with his place in this new universe. When the Enterprise-D is threatened by the Dyson Sphere that trapped Scotty for so long, it’s up to him and the current Chief Engineer Geordi La Forge to save the ship and crew. One last miracle from Mr. Scott, he leaves to explore the galaxy, but not before imparting some words of wisdom to La Forge. 

Star Trek: Deep Space Nine - “Emissary” 

Sisko sits in a conference room onboard the Enterprise-D. Picard is facing out a window, looking away from him.
Star Trek: Deep Space Nine - "Emissary"

The pilot episode of Deep Space Nine begins during one of TNG’s darkest moments — Picard’s assimilation. As the battle of Wolf 359 rages on, Commander Sisko suffers an immense loss, his wife Jennifer. This moment sets up the catalyst for his journey through the episode, especially as he meets Picard face-to-face. While most view Picard with reverence, Sisko is furious – and rightfully so – over the former's role in his wife’s death. As Sisko faces his trauma through a later conversation with the Prophets, he ultimately faces Picard and accept his commission to be commander of the station. 

Star Trek: Deep Space Nine - “Trials and Tribble-ations” 

Captain Sisko talks to Captain Kirk on the bridge of the Enterprise. Uhura looks on in the background.
Star Trek: Deep Space Nine - "Trials and Tribble-ations"

What do you do when a vengeful Klingon uses a Bajoran Orb to travel back in time to kill Captain Kirk? Travel back in time as well, disguise yourself with classic TOS uniforms, and try to stop him, of course! The crew of the Defiant must stop Arne Darvin, the villain from the classic episode “The Trouble with Tribbles,” from exacting revenge on Kirk from the future. As Sisko and his crew try to stop him, they wind up in the background of key moments from the episode. It’s a joyous episode, and a delight for fans of both TOS and DS9. 

Star Trek: Voyager - “Flashback” 

Janeway and Tuvok confer as Captain Sulu watches them.
Star Trek: Voyager - "Flashback"

Captain Sulu takes the stage in the Tuvok-centric episode “Flashback,” which also features former-Yeoman-turned-Commander Janice Rand. As Tuvok deals with a virus, he reflects on his days aboard the U.S.S. Excelsior during the events of the film Star Trek VI: The Undiscovered Country. This gives us a chance to see Sulu at his full, captain-ly power, which is always a sight to behold. It also provides us insight into Tuvok’s backstory, as he trusts Janeway to join him in a mind meld to save his life. 

Star Trek: Voyager - “Pathfinder” 

Lt. Barclay smiles at Commander Troi.
Star Trek: Voyager - "Pathfinder"

Lt. Barclay and Commander Troi take center stage as Barclay begins to obsess over the crew of the U.S.S. Voyager. Involved in the Pathfinder project as it attempts to make contact with Voyager, Barclay develops a Holoprogram of the crew, which he befriends.

Ultimately, Barclay is able to contact Voyager, bridging the gap between the ship and Starfleet. Overjoyed, the Voyager crew holds a small party for Barclay; even though none of them know him personally. For his relentless work, he is made an honorary part of the ship’s crew. 

Star Trek: Enterprise - “These Are the Voyages…”

Commander Troi and Commander Riker smile at each other at the founding of the Federation.
Star Trek: Enterprise - "These Are The Voyages..."

It might seem strange to use a series finale as a potential jumping on point for a series, but this episode is the only time that a character from another series appears in Star Trek: Enterprise due to the series being a prequel.

Using the Holodeck as a framing device, Commander Riker and Commander Troi watch the beginnings of the Federation through the eyes of Archer and his crew. This is later referenced in the first season finale of Lower Decks, “No Small Parts,” as Riker says he’s late to the Bridge because he was in the Enterprise Holoprogram yet again.  

Julian Gardner (they/them) is on the editorial team for StarTrek.com.

Star Trek: Lower Decks streams exclusively in the United States and Latin America on Paramount+, and is distributed concurrently by Paramount Group Content Distribution on Amazon Prime Video in Australia, New Zealand, Europe, Japan, India and more, and in Canada on Bell Media’s CTV Sci-Fi Channel and streams on Crave.

Star Trek: Discovery currently streams exclusively on Paramount+ in the U.S. Internationally, the series is available on Paramount+ in Australia, Latin America, the UK, and South Korea, as well as on Pluto TV in Austria, France, Germany, Italy, Spain, and Switzerland on the Pluto TV Sci-Fi channel. It will also stream exclusively on Paramount+ in Italy, France, Germany, Switzerland and Austria later this year. In Canada, it airs on Bell Media’s CTV Sci-Fi Channel and streams on Crave. Star Trek: Discovery is distributed by Paramount Global Content Distribution.

Stay tuned to StarTrek.com for more details! And be sure to follow @StarTrek on Facebook, Twitter, and Instagram.

Star Trek: Lower Decks