Although Star Trek: Discovery was positioned as a prequel to Star Trek: The Original Series, the edgier nature of the series immediately drew comparisons to Deep Space Nine. And, now that Discovery has jumped well beyond the 23rd century, it’s in the strange position of being a prequel that is now a sequel to all of Trek. In Season 3, Episode 4, “Forget Me Not,” Discovery doesn’t just seem like a sequel to DS9 in its style or grittiness, it literally revisits one of DS9’s most famous planets, the Trill homeworld. So, if you felt like you were watching a far-future DS9 sequel, you’re not wrong! Here’s all the Easter eggs and references to the entire canon of Trek (but mostly DS9) in “Forget Me Not.”

Senna Tal’s name

The Starfleet admiral whose message Burnham intercepted is named “Senna Tal.” In episode 3, we learned that Adira carried Senna Tal’s symbiont inside her, which means the symbiont itself is named “Tal” and the male Starfleet Admiral was Senna. This is just like the difference between Jadzia Dax and Curzon Dax. Of course, Adira doesn’t start the episode as “Adira Tal,” that comes later, when we also learn about Grey Tal.

Bajoran Hasperat

Adira says she knows how to cook a “mean Bajorian Hasperat.” This is a spicy Bajorian food featured throughout DS9, but first mentioned in the TNG episode “Preemptive Strike.” So, if you seem to recall Ro Laren talking about Hasperat on TNG before Kira did on DS9, you’re right! That said, we never actually saw Hasperat until DS9, at which point it appeared to look like a burrito. On some level, saying “Bajoran Hasperat” might be a little redundant, but we can forgive poor Adira; her memory is really scrambled! 

“There’s no precedent”

Dr. Culber says “There’s no precedent” for a human having a Trill symbiont in their body, but TNG Trekkies might be upset because they know there totally is. In the TNG episode “The Host” (the first Trill episode ever) Will Riker took on the symbiont of Ambassador Odan. So, did Discovery ignore this? Nope! In fact, Culber saying this makes perfect sense. Dr. Crusher helped put the Odan symbiont in Will Riker in 2367. Dr. Culber’s medical records come from the year 2257, plus the Sphere Data, which is considerably older. So, although Discovery now takes place in 3188 (or 3189), the information Culber has is from 2257 or older. With that in mind, it would have actually been weird had Culber known about Riker. 

The planet Trill and the caves of the Caves of Mak’ala

It’s been a minute since we’ve visited the Trill homeworld. In Deep Space Nine, Jadzia had to return to the planet Trill in the episode “Equilibrium.” The caves that Burnham and Adira visit, complete with symbionts floating in those milky pools come from that episode. 

The tardigrade on the Glenn

Talking to Tilly about the Spore Drive, Stamets mentions he was unable to find an interface for making the hub work “before we discovered the tardigrade on the Glenn. This references the episodes “Context is For Kings” and “The Butcher’s Knife Cares Not For the Lamb’s Cry,” from Discovery Season 1. In those episodes, the crew found a giant mutated Tardigrade nicknamed “Ripper” on the sister-ship to the Discovery; the USS Glenn.

“932 years of technological advancement”

How long has it been since the Spore Drive was made operational? 930 years or 932? Well, Discovery Season 1 mostly took place in 2256. Then Season 2 was in 2257. Then we were told that the crew was going to jump ahead 930 years. But, we also know that there’s been one extra year in there — Burnham’s gap year. So, 932 years work: you’ve got the 930-year jump, plus the year prior (2256) and then, the gap year, and that makes 932. Still, it’s a little confusing if at this point we’re at the end of the year 3188 or starting to cross over into 3189? If Burnham arrived at the beginning of 3188 in “That Hope Is You Part 1,” then we could still be in 3188. Or maybe not! So, is it actually 933 years of technological advancement? 

“A subspace domain”

Stamets mentions that the mycelial network is a “subspace domain,” meaning that it’s inherently not part of “normal space.” While subspace domains are made-up sci-fi, dark matter is closer to being real. What Stamets is kind of saying is “Dark matter exists in real space, and all the spore drive stuff happens in not-real space.” He’s not wrong.

Culber and Burnham compete for who has had a harder time at life

When Culber suggests that Burnham go with Adira to the surface of Trill, the convo goes like this. Culber: “She’s had everything she knows stripped away, I think you understand that.” Burnham: “I think you do too.” Culber’s comments that Burnan “understands that” probably references the idea that Burnham was once court-martialed and sent to Federation prison, way back in the episode Discovery Season 1 episode “Battle at the Binary Stars.” But, Burnham’s retort “you do too,” references the fact that in Season 2, Culber came back from the dead and had an entirely new body reconstructed from the mycelial network.

Burnham and Adira take a shuttle down to the planet

Why don’t Burnham and Adira beam down to the surface of Trill? Well, in the TNG episode “The Host,” Trill couldn’t use the transporter because it could damage the symbiont. But, in DS9, Dax beamed up and down all the time. We also saw Adira beam onboard Discovery in the previous episode. Are they slightly more worried now? Just being careful? 

No records of a joining between a human and a Trill symbiont 

The Trill guardians say that in “2,000 years there’s no single recorded instance of a joining” between a human and a symbiont. Next Generation fans know this is slightly wrong. Riker was joined with the Odan symbiont in “The Host.” Seems like the Trill government didn’t want anyone to know about that, hence it not being a “recorded instance.” In this scene, it’s also mentioned that “forced separation could kill the host.” This idea was established in DS9 numerous times.

“We are not Federation members”

The Trill guardians mention that they are not part of the Federation, which seems similar to the status of Earth in Episode 3. There’s just one difference, although we’ve seen several Trill serve in Starfleet throughout the years, it was never explicitly stated in onscreen canon that the planet Trill was part of the Federation. (Though some non-canon books do put it in the Federation as of 2285, the same year as The Wrath of Khan.)

Viable Trill hosts

Not all Trill are “joined.” In the DS9 days, we were mostly told that it was very hard for humanoid  Trill to be suitable to carry symbionts. However, in the DS9 episode “Equilibrium,” we learned that this was a myth, and that actually there were plenty of viable hosts. Is it possible this myth has been perpetuated even further? One of the Guardians says Adira could be the future because “We no longer have enough viable hosts.” If this is the truth, then something has radically changed with Trill biology. 

That wasn’t Federation protocol!

Adira notices that Burnham takes out the Guardians pretty quickly with her phaser. Burnham says “they’ll be fine.” This means her phaser was on stun, and we know that because it had little blue light illuminated and not a red light.

What’s you and what’s all the other hosts?

In the flashback, Adira asks Grey (Ian Alexander) which parts of his personality are coming from him and which parts are coming from the previous hosts of the Tal symbiont. When Ezri Dax was first given the Dax symbiont, she had similar questions about what she was really like. In fact, on some level, the origin story of Adira is similar to Ezri: Both became joined Trill because of an emergency.

Medical bots were foreshadowed in the new credits

The emergency medical robots that help perform the surgery on Grey to put the symbiont in Adira were previously glimpsed in the opening credits of Discovery Season 3, starting with “That Hope Is You Part 1.” This Easter egg is similar to Discovery Season 2 when the Red Angel and the time crystals were both teased out in the opening credits.

Previous hosts of Tal have various “new” Starfleet uniforms

Counting Admiral Senna Tal, at least two other of Tal’s previous hosts were Starfleet officers. We see one woman in a teal-colored Starfleet uniform that appears to precede the era of Senna Tal’s uniform. But, we also see a man in a Starfleet captain’s uniform who is very much from the era of Star Trek: Picard. This seems to imply that the Tal symbiont is at least 789 years old, but actually, probably much older. Did a previous host of Tal know characters from TNG or DS9? Is Dax still around?