It's been a dark year for Deep Space Nine fans. While 2019 offered plenty of opportunities to celebrate 20 years since the show's finale, it's come with its share of pain as well. Just this past September, we lost Aron Eisenberg, who created one of Trek's most empathetic characters with the Ferengi street-rat-turned-Starfleet-officer Nog. And yesterday marked the passing of René Auberjonois, veteran character actor and the person behind Deep Space Nine's irascible, shape-shifting Constable Odo.

Before filling the mud-brown booties of Terok Nor's gruffest occupant, Auberjonois was already a well-established presence on stage and screen. In the '60s, he was a mainstay in professional theater; he won a Tony in 1970 for the Broadway musical Coco the same year he broke out in Robert Altman's M*A*S*H as Father Mulcahy. He'd continue to play a regular role in Altman's stable of actors, in films like McCabe & Mrs. Miller and Images, before breaking out as the fussy Clayton Endicott III on TV's Benson in the '80s. But for many sci-fi fans, it's his seven-year turn as Odo that we remember most.

Auberjonois was an incredibly versatile performer — capable of aching vulnerability and imperiousness, often at the same time — which was perfect for the role of Odo. The series established Odo early on as the no-nonsense sheriff of the frontier town that was DS9, a gruff administrator who kept the Promenade in order with a tight fist.

But even in the first episode, "Emissary," we learn that Odo's not the middle-aged, world-weary taskmaster Auberjonois' age would belie (he was in his 50s when he played the role): He was a child, orphaned in an unknown land and taken in by a people who knew nothing of where he came from. His look and affectations came from what he observed of the Bajorans who studied him (particularly Dr. Mora Pol, who acted as a flawed father figure in the character's few appearances), and his genetically ingrained desire for order drew him to a career in law enforcement.

Video of Deep Space 9, Odo shapeshifting

Every Trek show has at least one nonhuman character who serves as a vehicle for exploring the human condition from an outside perspective: Spock, Data, Seven of Nine, the EMH. For Deep Space Nine, that was Odo, and he did it from an angle totally unlike his counterparts. Where Data yearned to become as human as possible, Odo rejected the niceties and quirks of "solids," treating everyday behaviors with a curious disdain. He took the form of humanoids, but could never quite master the face, leaving his visage uncannily blank and smooth.

Food, love, romance — all of it was greeted with a skeptical "harumph," at least early in Odo's time on the station. (Auberjonois bristled at the show's writers writing his "harumphs" into their dialogue in later seasons; he knew when Odo would really harumph.)

But his newfound relationships with the crew of Deep Space Nine allowed Odo to grow outside the confines of his previous job as security chief on Terok Nor, when the Cardassians held the station during the Bajoran occupation.

The mystery of Odo's origins was solved fairly quickly in the series — the Season 3 opener, "The Search," revealed that his people, the Founders, were the leaders of series baddies the Dominion. But Auberjonois and the writers found new avenues to explore Odo in light of this information. Suddenly, the lost boy had to work even harder to set himself apart from his people, and the solids he viewed with cautious distance became his family. Odo was a character afraid to open up to other people lest he let his own guard down, and the moments when that facade cracked are some of the most rewarding in all of Trek history.

Odo was at the center of Deep Space Nine's most serious episodes, and some of its lightest. Take the interrogation scene between him and Garak in "The Die Is Cast," for instance, or the confession of his guilt at his role in the Occupation in "Things Past," all beautiful showcases for Auberjonois' ability to convey Odo's pain and yearning. But for every one of those, there are larks like "Little Green Men" or "Take Me Out to the Holosuite" (where he approaches the role of baseball umpire with relish). And don't forget "His Way," where he learns to let his combed-back hair down and play the piano at Vic's bar (and start a relationship with Major Kira in the process).

Video of DS9 - don't touch the umpire

Then there's his dynamic with Quark, the sleazy Ferengi bartender who delighted in making Odo's life a living hell, and vice versa. DS9 was all about the complexities and intensity of its character relationships, and the bristling back-and-forth between Odo and Quark was a testament to that focus. Between all the backstabbing, scheming, and threats of arrest, it couldn't have been clearer that, on some unspoken level, the two loved each other.

They were the best kind of adversaries: those who delight in the chase and find a deep understanding of each other as a result. It was also a beautiful showcase for both Auberjonois and Quark actor Armin Shimerman, who'd prove one of Auberjonois' most capable scene partners (and a close friend).

It's hard to talk about Odo's appeal as a character without talking about Auberjonois himself, who was central to bringing out the kind of yearning pathos the shapeshifter required. In a franchise filled with rubber foreheads and impenetrable makeup, Auberjonois found a way to emote through face-shrouding prosthetics. There was dignity in Odo's stillness, and emotion in those deep, sad eyes of his. Over seven years, we got to see Odo grow from one-dimensional space sheriff to savior of his people and the man who ended the Dominion War.

The final moments of Ira Steven Behr's 2019 documentary What We Leave Behind, a postmortem on the show's legacy, are fittingly left to Auberjonois. "Well, at least now in my obituary it's not gonna say 'best known as Clayton Endicott III on Benson.' Because he was a wonderful, funny character, but he was a nitwit. And so now … what do I say?" The impact of his character on both his life and the lives of the show's fans leaves him visibly speechless. Considering the impact he had on the series, and the many fans who mourn him today, I don't blame him. He'll be sorely missed, but in the legacy of one of Star Trek's most enduring, complex characters, he'll live on.