Vulture’s fourth annual TV Awards honor the best in television from the past year in three major categories: Actor, Actress, and Show. The shows that were considered had to be ongoing, which disqualifies limited series and series that ended their runs in the past year. They also must have premiered before June 25, 2017.

There are many reasons to praise Graeme Manson and John Fawcett’s science-fiction thriller Orphan Black, which is barreling through its final season on BBC America, but the first is that it gave its brilliant star Tatiana Maslany the role(s) of a lifetime. This piece will make a case for Maslany as not just the most impressive actress on TV today but also the most fun to watch, so we should start by reiterating something that every fan of the show has said or thought at one point or another: No matter how many hours of Orphan Black you watch, and no matter how aware you are of the behind-the-scenes machinations that allow one performer to interact with multiple versions of herself, there are still stretches when you forget that almost every clone on the show is played by the same actress.

In five seasons, we’ve met a small army of Orphan Black characters who were created as part of the mysterious Project Leda. Most are portrayed by Maslany: The major players include Sarah Manning, a street punk raised in an English orphanage who serves as our guide through the show’s labyrinthine conspiracies; the Canadian-accented Beth, a tough, depressive cop whose identity Sarah assumes; Sarah’s twin sister Helena, an Anglo-Ukrainian raised in a convent, used as a birth surrogate, and trained to kill clones, but became a wild-card “sestra” of the others; Cosima, a tattooed, dreadlocked American lesbian and Ph.D. student who suffers from a respiratory illness; Alison, a tightly wound former valedictorian and cheerleader who married her college sweetheart Donnie (Kristian Bruun) and adopted two kids, and who blurts out Marge Gunderson–style folksy declarations (“What the dickens?”); Rachel, a cold, manipulative “pro-clone” clone raised as a child by the Neolution corporation, who acts as a foil to the rest; Katja, an icy German with burned-out-rock-star charisma who tracked Beth down and tipped her to the conspiracy to kill off the other clones; Krystal, a comic relief and/or exposition character who remains blissfully unaware that she’s a clone even as she feeds information to the others; Tony, a transgender clone who identifies as male; and Jennifer, a high-school teacher and swim coach who died of medical complications that also afflict some of the other clones, and whose tragic story is revealed through video diaries.

Many actors who play multiple roles rely on hyperstylized voices and movements to sell the notion that we’re looking at a different character each time the camera cuts or moves to reveal another iteration. Sometimes this is part of the fun: When we watch, say, Mike Myers, Eddie Murphy, or Martin Lawrence play more than one character in a cartoonish Hollywood lark, the laughs stem partly from our recognition that the characters are all played by the same cutup. But it’s rare to watch a hall-of-mirrors performance that allows us to stop thinking of it as a comic or dramatic stunt and instead concentrate on what’s happening to each individual character intellectually and emotionally from one minute to the next.

That’s exactly what Maslany achieves on Orphan Black. Some of her characters are “small” in a dramatic sense, and others are big, but none are caricatures. We believe in each of them as people.

1. Rachel’s Address (Episode 501, “The Few Who Dare”)

Here’s a relatively restrained example of Maslany’s wizardry, a two-minute bit from the season-five opener. Rachel comes down the steps to address the inhabitants of the Revival camp while Cosima looks on from the audience, and then, near the end, Sarah appears, her face bloodied after being attacked in the woods by a goblinlike mutation creature, holding a spear and listening from behind the edge of a wall.

Cosima is, as always, a great listener and watcher, with the empathetic but laser-sharp focus of a good therapist or grad-school adviser. You can see by the closeups of Cosima in the crowd that this character is never content just to absorb the facts of whatever’s happening; she probes the sounds of words and the emotions in people’s faces for additional insight. Rachel, meanwhile, is intoxicated by power and attention and exudes the serenity of a recently coronated queen. Her flutey voice, bordering on a rich society lady in a 1930s movie, nearly trembles with the thrill of being literally and figuratively elevated over everyone else. When Sarah makes her wordless appearance, she exudes a predator’s energy. It’s as if Braveheart had showed up, pissed off and ready for action.

2. The Serum Injection (Episode 501, “The Few Who Dare”)

Here we have a series of direct confrontations between the same clones who just observed each other in the earlier scene. First, Cosima goes alone into a trailer full of medical supplies to inject herself with stolen treatment serum, only to be surprised by Sarah, who unbeknownst to her had snuck into the camp in the previous scene. Sarah (who, over time, seems to have fused with the personality of Beth, the cop she impersonated) enters like a battered action hero, limping and out of breath. When she sees Cosima’s needle, she says, “You meant to put that in your uterus” with a movie tough guy’s hardness. Cosima’s surprise at seeing Sarah is mingled with concern at how bad she looks. Here, as in all Cosima-Sarah scenes, you appreciate the difference between the characters’ voices: Sarah’s husky cockney and Cosima’s higher-pitched tone, with its slight Valley Girl inflections and traces of vocal fry.

Then Rachel comes in, her slight limp ironically echoing Sarah’s, exuding malevolence but also an affinity for the clone she’s intimidating. (They are genetic sisters, after all.) When she offers to inject Sarah, her iciness is leavened by a rooting interest that’s nearly motherly. When the needle goes in, Maslany’s Cosima lets a single tear spill from her left eye.

3. The Face-Off (Episode 502, “Clutch of Greed”)

In another strong Rachel-Sarah scene, much of the tension comes from the clones’ starkly different screen presences. As Rachel spells out terms for reuniting Sarah with her daughter, Kira, the captor seems to inch through the room like a snake while her captive moves with more spontaneity, despite not having anywhere to go. Like the variations in the characters’ English accents — Rachel’s “SHED-ules,” Sarah’s “She’s a li-UHL girl” — their way of moving through space illustrates class differences, not just the relative power of each clone. Rachel’s posture is upright, her squared shoulders contrasting with Sarah’s slightly rounded ones (as if she’s anticipating a blow). Because Rachel stares unblinkingly at the current focus of her attention, whenever she shifts her eye line — as when she says, “It’s all down to you now, Sarah,” then looks up from Kira to her mother — it feels like a threat-level escalation. When Sarah slaps the teacup from Rachel’s hand (in a wide shot!), Rachel is serenely unfazed. That half-smirk is chilling.

Maslany is part of a tradition of stars appearing in multiple subplots of the same story and sometimes acting with (and against) themselves in a scene. Film and TV history are filled with examples of actors playing two or more characters in the same narrative. Peter Sellers was the reigning champ during the middle part of the last century, tackling three vivid roles in Dr. Strangelove and playing bumbling inspector Jacques Clouseau plus assorted, deliberately ridiculous “undercover” characters in the Pink Panther series. We’ve seen a number of examples on TV drama in recent years, including Sarah Paulson as conjoined twins on FX’s American Horror Story: Freak Show, Kyle MacLachlan as three iterations of FBI Special Agent Dale Cooper on Showtime’s Twin Peaks: The Return, and Ewan McGregor as twin brothers on season three of FX’s Fargo; this fall, James Franco will play yet another set of twins on HBO’s Times Square period drama The Deuce.

As impressive as all these multiple performances are, though, they’re overshadowed by Maslany’s work in the same vein.

It’s also true that these sorts of performances don’t occur in a creative vacuum. Every screen actor depends to some extent on collaborators in the crew as well as the ensemble cast. Maslany would be the first to tell you that when she plays multiple roles on Orphan Black, she’s standing atop a scaffolding built by other professionals: screenwriters, costumers, makeup artists, gaffers, placeholder-doubles (Kathryn Alexandre has been Maslany’s main stand-in and “scene partner” through all five seasons), and especially directors and cinematographers. The use of motion-controlled cameras (perfected during the production of David Cronenberg’s 1988 film Dead Ringers, starring Jeremy Irons as twin doctors) helps sell the illusion, allowing filmmakers to repeat elegant movements precisely, so that twin characters could appear onscreen together in a moving composition instead of a locked-off wide shot that makes savvy viewers think, “Aha, this is where the trickery starts.”

All that said, Orphan Black’s illusion would not persuade if the show hadn’t cast its lead parts with an actress who treats each role as its own detailed assignment, wherein the goal is to make every woman so clearly delineated, and inhabited with such seeming ease, that we could envision a separate series being built around just one. Maslany won an Emmy for Best Actress last year, but she deserves another before she hangs up the show’s astonishing selection of wigs and footwear. Never in television history has a single performer portrayed so many characters interacting within the same story, week after week and season after season, often within the same screen space, and made it seem like no big deal at all.

Take a second to think about what’s involved here. It’s staggering. Performance becomes fiendishly complex when the same actor plays more than one part in the same show or scene. In addition to acting, Maslany has to serve as part psychologist, part shadow director, and part continuity supervisor, judging every performance in relation to every other performance to make sure there’s no blurring or overlapping, while making sure to leave physical or temporal space for every other. This is an aesthetic challenge, but also an athletic one. There’s an aspect of dance involved: You constantly have to remember where every other version of you is supposed to be at every second, otherwise you can’t accurately time whatever a particular version of you is supposed to do at an exact moment. It’s like classical music that follows a prewritten score measure for measure, but in the end we have to feel as if it was all improvised in the moment, otherwise it would be intellectually stimulating but not emotionally involving.

Not only has Maslany nailed every facet of this challenge from season one of Orphan Black, she’s gotten to the point where each clone has such specificity and depth that if the series suddenly decided to focus primarily on Rachel or Alison or Cosima in its final episodes, I doubt too many viewers would complain. Maslany embellishes each character with so much detail that we’re already wondering what’s going on in their heads when they aren’t speaking, or when they aren’t even onscreen.

Before settling on Maslany, I made a handwritten chart comparing different lead actresses in terms of their range and versatility, in particular their ability to modulate within a scene that calls for wildly different modes (farce, gritty psychodrama, feverish melodrama, and so forth). Perhaps most important, I considered their ability to make you believe that their character has an interior life, to make you imagine their character existing before or after the scene in which they happen to appear. Writing, direction, and other elements of storytelling come into play, of course, but I did my best to concentrate on what the performers were doing with their faces, bodies, and hands in a scene: how they acted and reacted, how they spoke and listened.

When I pitted Maslany against my current TV favorites — Elisabeth Moss in The Handmaid’s Tale, Ellie Kemper on Unbreakable Kimmy Schmidt, Phoebe Waller-Bridge on Fleabag, Felicity Huffman and Regina King on American Crime, Taraji P. Henson on Empire, Robin Wright on House of Cards, and Keri Russell on The Americans — Maslany came out ahead by dint of the sheer number of performances she gives during any given episode and the subtle colorations she brings to each one. As superb as these other performers are, they’re mostly doing arithmetic, while Maslany is doing something else. I’m tempted to call it higher math, but it’s more like she’s custom-building her own Rubik’s Cube and then manipulating it with such lightning speed that, by the end of each episode of Orphan Black, she’s got six solid sides again.

The only other female performer on TV who made me agonize over my decision was Carrie Coon, who appeared simultaneously this season as Gloria Burgle, a wounded but steely policewoman on season three of FX’s Fargo, and as the self-destructive and tantalizingly opaque Nora Durst on the final season of HBO’s The Leftovers. (The latter’s finale is built around Coon, and builds toward one of the most mesmerizing close-up monologues since Ingmar Bergman was shooting Liv Ullmann in black-and-white.)

It’s here that the body-of-work aspect served as a tiebreaker. We’re impressed, as well we should be, that Coon — who we gave the Best Actress award last year — was equally convincing in two different roles on two different series; meanwhile, though, Maslany was playing anywhere from five to eight characters in a single episode, and investing each one with such conviction that I could picture her being spun off into a separate series. (Imagine a demented sitcom built around Alison, with Amy Poehler as showrunner.)

A comparison of Maslany’s work and the work of other notable performers who’ve played multiple roles on the same TV series led me to the same conclusion. Sarah Paulson on American Horror Story: Freak Show, Kyle MacLachlan as multiple Coopers on the new Twin Peaks, and Ewan McGregor’s work as twin brothers on the most recent Fargo (opposite Coon) are all ambitious, fun, and sometimes sublime. But they all seemed less impressive when I went back and looked at the countless, marvelous Orphan Black clone scenes that overlapped or predated them: Sarah, Alison, and Cosima in conversation in season one, episode three; Helena singing “Sugar, Sugar” in the car with Sarah from season two; Sarah playing Rachel opposite Alison playing Sarah in the season-three opener; Helena’s season-three baby shower, which imagines other clones through the subjective viewpoint of Helena (especially tricky because Maslany is not just playing different characters, but one character’s idea of the others); and the season-four clone dance party. If you could somehow combine the precision, focus, and intensity of Coon with the knockabout goofiness of a chameleonic sketch comedian like Saturday Night Live’s Kate McKinnon, you’d get something close to what Maslany delivers each week, and has delivered since 2013.

I should admit here that Maslany’s body of work over five seasons of Orphan Black carried weight in the final call. If that turns this into the TV version of Al Pacino’s Scent of a Woman Oscar, so be it. As Maslany told Vulture’s E. Alex Jung this year, “We wanted our gimmick to be invisible.” It is, and it’s ultimately Maslany who supplies the invisibility cloak that allows us to suspend our disbelief while watching Orphan Black. Her mix of invention and empathy ensures that we never think about all the work that goes into making the series, as well as the physical labor and imagination that she puts into every moment.