The Kelleruns made only one appearance in Deep Space Nine, but what can that tell us about Captain Rayner in Star Trek: Discovery season 5?

Star Trek: Discovery‘s new character Captain Rayner (Callum Keith Rennie) is a member of Star Trek: Deep Space Nine‘s Kellerun species, which has interesting implications for season 5. The Kelleruns only appeared in one episode of DS9, “Armageddon Game”, as aliens-of-the-week. The episode was an important one for Chief O’Brien (Colm Meaney) and Dr. Bashir (Alexander Siddig), but it didn’t establish the Kellerun species as an exciting new addition to the canon of Star Trek alien species. It’s the lack of further information about the Kelleruns that inspired the decision to include them in Star Trek: Discovery season 5.

However, there’s enough revealed in Star Trek: Deep Space Nine season 2, episode 13, “Armageddon Game” to give some clues as to what to expect from Captain Rayner in Star Trek: Discovery season 5. In return, showrunner Michelle Paradise has revealed to TrekMovie that season 5 will reveal new information about Captain Rayner’s alien species and their culture. Read her quote below:

[Captain Rayner is] a Kellerun. We were looking for a species that not a lot had been done with them. We definitely wanted another non-human on the ship and taking care of things. And Kellerun is one that had not been explored a whole lot. So we were able to also build some backstory for him and for his planet that we’ll come to learn more about later.

What Happened To The Kelleruns Between DS9 And Discovery?

In the Star Trek: Deep Space Nine episode “Armageddon Game”, the Kelleruns requested Federation assistance to dispose of their devastating biological weapons, following a long war against the T’Lani. Both species were non-Federation races, and didn’t enamor themselves to Starfleet by trying to have O’Brien and Bashir killed. The Kelleruns were never heard of again, but because O’Brien and Bashir were the only people to have knowledge of how the biological weapons worked, it’s possible that peace with the T’Lani remained in place.

800 years later, and relations have clearly improved between the Kelleruns and the Federation by the time of Star Trek: Discovery season 5. It’s not known how the Kelleruns and T’Lani responded to the Burn, nor if both species ended up joining the Federation. Rayner is a serving officer, meaning that, at the very least, Starfleet now accepts Kelleruns among their ranks. Though he could be an exception, like Captain Saru (Doug Jones) or Lt. Nog (Aron Eisenberg). These questions about the Star Trek: Deep Space Nine aliens will likely be answered through Captain Rayner and his backstory in Discovery season 5.

How Will Captain Rayner’s Kellerun Heritage Impact Discovery’s Treasure Hunt?

From what was seen of the Kelleruns in Star Trek: Deep Space Nine, their politicians follow a scorched-earth policy when it comes to matters of security. Ambassador Sharat (Peter White) ordered the deaths of anyone who had knowledge of the biological weapons so that they could never be made again. It’s an extreme approach, and raises questions about how Captain Rayner will respond to revelations about Star Trek: Discovery‘s season 5 treasure. It’s been teased that the prize that Burnham and the Discovery crew seek should not fall into the wrong hands, so how far will Rayner go to ensure that it doesn’t?

It’s certainly possible that Kelleruns take a less extreme approach in the 32nd century, but the clips and trailers released so far suggest otherwise. In the clip of Burnham riding a starship, Rayner’s ship appears overhead, and is determined to capture L’ak (Elias Toufexis) and Moll (Eve Harlow), no matter the cost to Michael and Rayner’s crew. This suggests that Rayner may have much in common with his predecessor from Star Trek: Deep Space Nine, perhaps creating a more antagonistic relationship with Burnham in Star Trek: Discovery season 5.