The Kelpiens and the Ba’ul of Star Trek might seem like polar opposites, but they’re similar in ways that have led to a disturbing history between the two. Each species views the other as the deadliest predator they have to fear on the planet of Kaminar. For the Kelpiens, the Ba’ul are the predators that keep them in a state of fear through oppressive, yet supposedly unavoidable, means. These mysterious beings are characterized by the black oily substance that covers them. When they’re not in their aquatic habitat, the Ba’ul are charactized by gangly limbs, red eyes, tendrils on their heads, and a protruding spine.
When Star Trek fans meet them in Discovery, the Ba’ul oversee the ritual sacrifice of the Kelpiens to achieve Great Balance across the planet. They’ve established a world order in which the Ba’ul – known by the Kelpiens as the Watchful Eye – are natural predators of the Kelpiens, and claim that maintaining this way of life is what helps Kaminar survive. The twist? The Kelpiens are only prey because they’ve been made to believe so over thousands of years. Fans learn that the Kelpiens are the real predators of Kaminar, and the Ba’ul created this system out of a desperate bid to survive the Kelpiens hunting them to extinction.
The first time Star Trek: Discovery fans meet Saru (Doug Jones), he is the first Kelpien to serve in Starfleet. Like all of his people, Saru is characterized by long gangly limbs, a bald head, and smooth orange-brown skin as well as enhanced senses. Perhaps most distinctively, he’s known for the threat ganglia protruding from the back of his head in the form of five pairs of tendrils. These are activated into a more flared state whenever he’s within ten kilometers (~6 miles) of potential predators with dangerous intentions toward him or those around him. In season 1, episode 8, “Si Vis Pacem, Para Bellum,” Discovery shows Saru able to run up to 80 kilometers (~49 miles) per hour when his prey instincts kick into high gear.
Unfortunately, these instincts can't protect the Kelpiens from their vahar'ai. For many years, they’re told that this is the period of extreme pain they must endure before they’re chosen by the Ba’ul to be sacrificed in a culling for the greater good, lest they lose themselves to madness. Then, in season 2, episode 4 “An Obol for Charon,” Saru goes through vahar'ai, and asks Michael Burnham (Sonequa Martin-Green) to remove his threat ganglia to end his life before the pain drives him mad. However, it turns out that without them, life doesn’t so much as end for Saru as it takes a drastically different turn.
It all comes to a head when the crew makes the shocking revelation that the Kelpiens are the native predators of Kaminar. In season 2, episode 6, “The Sound of Thunder,” Burnham and Sylvia Tilly (Mary Wiseman) are combing through the ship’s historical database when they learn the 2,300-year-old-truth. For the Ba’ul, the Kelpiens are a group of predators barely kept subdued by a violent yet necessary system. Where the Andorians and the Aenar live in relative peace on Andoria, the Kelpiens and the Ba’ul are a long way from unity.
It’s only through their oppression at the hands of the Ba’ul that the Kelpiens eventually evolved the ability to sense when danger is near. As the Kelpiens and the Ba’ul clash in a deadly fight for dominance, only the appearance of the mysterious Red Angel subverts the world-ending consequences of this battle. Saru and his sister Siranna (Hannah Spear) stand shoulder-to-shoulder as the world they knew collapses, and a new way of life in which Kelpiens can be what they were always meant to be, arises at last.
Meanwhile, the Kelpiens of the mirrorverse have presumably not met their day of reckoning. In fact, in season 1, episode 12, “Vaulting Ambition,” Emperor Philippa Georgiou even invites Burnham to dine on Kelpien ganglia as part of a fancy meal. This is especially sinister considering the work Burnham has put in to revive her friendship with Saru, who’s like a brother to her, only to enter a world in which she has to treat him and those like him as if they’re beneath her.
The Ba’ul of this twisted version of the world have made Kelpiens a staple of fine dining rather than hunting them. Either way, though, they’re still being preyed on and even enslaved within the Starfleet Federation. It’s a far cry from the usual stalwart insistence on equality between beings throughout the galaxy. However, it makes sense that in a world where the only thing that matters is fulfilling one’s desires – for sex, clout, and promotions alike – there’s no such thing as wrong or immoral. The Ba’ul, on the other hand, are an unseen presence within the mirrorverse, known only for their contributions to the bleak reality of the Kelpiens.
The Kelpiens and the Ba’ul certainly aren’t the first species in the Star Trek universe to have strained relations. They certainly won’t be the last. What makes their relationship different, though, is that much of it has been steeped in power plays and lies. The Ba’ul simply wanted to survive being completely wiped out by the Kelpiens of old. Their methods may have been a series of rights violations, but desperation to survive has historically been known to exacerbate harmful tendencies in society.
Meanwhile, the Kelpiens were natural predators, doing what their instincts were driving them to do. While their treatment of the Ba’ul was unfair, they didn’t deserve to suffer for so long that even Kelpiens with no memory of their true nature were still being punished for the actions of their ancestors. Fortunately, Saru’s sister Siranna becomes a key element of both the Kelpien return to their true nature, as well as their unification with the Ba’ul under the Starfleet banner once Kaminar joins the Federation. In that way, the Kelpiens and the Ba’ul aren’t just like other Star Trek species warring for territory and a right to life. They’re a testament to sacrificing the battle to strive for peace.