It's a scene Homeland fans have seen seemingly millions of times before.

Carrie Mathison (Claire Danes) — the brilliant, bipolar superspy at the series' center — believes the only way she can figure out what's going on is to stop taking her medication. When she's having one of her manic episodes, she feels as if she can think more clearly and work more thoroughly. The challenge, as she explained to her new boyfriend in an earlier episode, is to avoid the crash that inevitably follows. But with his help, she thinks she can do just that.

And so, Carrie going off her meds is the meat of the third episode of Homeland's fifth season, "Super Powers," which is more than the repetition it seems to be. It considers Carrie through the lens of both her existence as a TV character (who will always have to face down her mental illness as long as the show lasts) and the country she represents (which, like her, keeps doing the same things and expecting different results).

"Super Powers" is one of the best episodes Homeland has ever done, transcending its roots as a seeming Emmy tape that allows Danes to dig more deeply into the show's themes than the program typically wants to do. It nicely sets the stage for the rest of the muted but still intriguing story that follows.

But it's also a reminder of something that's easy to forget: Carrie Mathison is the most significant TV character of the 2010s.

By "significant," I don't mean "best"

Yeah, there have been better characters than Carrie this decade. There have been better performances than Danes's (though she remains tremendous, even when the material backing her up is not). And there have been plenty of better shows than Homeland.

But it's hard to overstate the seismic impact the show's first — and still best — season had on the TV industry. Danes won awards. Homeland almost immediately became a new obsession, and also won awards. Even the president said the series was his new favorite.

All of that is easy to forget now, in the wake of the bad decisions Homeland made in the back half of its second season and the entirety of its third, but it was once considered the next great TV show, with Danes as its electrifying star. Even around mid-season two, when the show was planting the seeds of its own destruction (and, I should admit, rebirth), Danes was turning out great work week after week after week.

But even as Homeland slowly disappeared from the headlines and ceased to be one of the major TV stories of the moment, the impact Carrie had on the creation of similar characters was substantial. Networks are still trotting out Carrie Mathison replicants, four years after Homeland debuted, and television as a whole has subsumed the character into its DNA in other ways.

Speaking broadly, there are two Carrie Mathison "types" — one more obvious than the other.

Type 1: A woman who works in a historically male industry and deals with veiled sexism

In many ways, this side of Carrie's personality is a continuation of some groundbreaking work done in the 2000s, particularly on programs like Grey's Anatomy and Damages, which broke from how shows about women in historically male industries had written those stories in the past.

The most common portrayal of this type is generally on a show like Cagney & Lacey, where the entire premise of the show hinges on women being part of a world they hadn't traditionally occupied. The center of Cagney & Lacey is the idea that the two women in the title are both women and police officers, something that was new and relatively provocative when the series debuted in the 1980s. These sorts of stories continued into the 1990s, perhaps reaching their apex in the late '90s with Ally McBeal, a show that took every bit of subtext it could find in that old model and highlighted it in screaming neon in the foreground.

But as more and more women entered the workforce, it was no longer that shocking to imagine a woman working in a police department, or a law firm, or a hospital. So the shows that followed turned interactions between genders — and the baked-in sexism of much of American life — into the subtext, only shining a spotlight on it in big, important, pivotal moments.

Homeland fits squarely within this tradition. When it comes to the show's premise, Carrie being a woman isn't intrinsic to what the show is trying to do. But in its earlier seasons, the more Homeland examined who she was in relation to everybody she worked with (both at the office and in the field), the more it made of the way she could be underestimated — and how she occasionally used that to her advantage.

Homeland also added a frisson of sexuality. In the series premiere, Carrie tried to sleep with her mentor, Saul, in order to get something she wanted, and later on she would sleep with men she was surveilling in an attempt to get them to open up more. Carrie was strong and competent and intelligent — but she was also constantly riding a knife's edge where her gender could be used to disparage her or push her into seemingly unstable behavior.

In this regard, it's probably more useful to view Carrie as someone who was part of a trend that already existed, but it's still hard to ignore that Homeland was such a seismic success in its early going. The TV industry tends to copy successful TV shows, and the current boomlet of terrific women protagonists in the medium (usually working in historically masculine fields) leads right back to Carrie and The Good Wife's Alicia Florrick, her rough contemporary.

Which brings me to the other, perhaps even more important, character Carrie was.

Type 2: A person struggling with a mental illness who, nonetheless, is hugely successful professionally

As I wrote about here, mental illness has long been a storytelling trope that television struggles with. Because mental illness never stops, only recedes, it's hard to tell dynamic stories, which require a natural rise and fall to satisfy. Television had tackled mental illness before, but usually in "very special" episodes or arcs. If a character struggles with depression or anxiety or the like, the person is usually non-diagnosed, the better to keep the show from hemming itself in with a list of recognizable symptoms and issues. (See also: Tony Soprano.)

But Homeland actually pinned a name to Carrie's condition, and suggested that it was so inextricable from the things that made her such an interesting character and such a great spy that to write it off as a "weakness" was too limiting.

The series — and its many imitators — has often danced too closely to the implication that Carrie is such a good spy because of her bipolar disorder, but in its best episodes and moments, it makes her condition a vital part of who she is and asks the audience to feel the same empathy for her that it would feel for any other character.

Carrie's bipolar disorder is by far the most revolutionary thing about the character in the TV landscape, and since she arrived, more and more TV characters have found their own diagnoses on shows both terrible (Kelly Reilly's character on the medical drama Black Box) and excellent (Hugh Dancy's character on Hannibal). TV comedy, in fact, has seen a recent mini-wave of women suffering from depression, as my colleague Caroline Framke wrote about here.

When you look at both of these character types, it's hard not to trace their roots back to Carrie and Homeland. And in that sense, the show's struggles to keep telling stories with the character at their center in recent seasons might prove instructive to those other series, many of which have already improved upon the ground Homeland pioneered.

It remains to be seen where Homeland will go next. Its current, fifth season displays a lot of the hallmarks of a final season, a sign that the show is slowly but surely wrapping up its story, but the show is such a success that it will surely run at least two more seasons, if not many more. Even though it continues to be well-reviewed, it primarily makes headlines when it's being called out for its stereotypical treatment of Arabic characters.

Yet even as Homeland slips out of the limelight, it's worth remembering just what it brought to television, especially in its spiky, brilliant protagonist. Carrie might not have lived up to all of her early promise, but she opened up new avenues for others to follow in her footsteps.