A simple epitaph for CBS legal drama The Good Wife, which ends its run Sunday, May 8, might say that it aired five good-to-great seasons and then two deeply troubled ones.

Of course, it's not that simple. It never is. The first half of the show's fourth season is filled with clunkers, and there have been brilliant episodes scattered throughout the final two years.

But the conventional wisdom is more or less right. The Good Wife fell apart early and rapidly in season six, when it pushed its protagonist, Alicia Florrick (Julianna Margulies), into politics, then didn't quite know what to do with her there.

It never recovered. And now, as it heads into its finale, it still seems a little scattered and unsure of itself.

But I'd argue the show's turning point came slightly earlier, near the end of season five, in a moment that almost everybody celebrates: the death of Will Gardner. Without him, the series was never the same.

Why Will's death changed everything

Will's death and its effect on the show are tricky subjects to talk about, because it often sounds like I'm reducing The Good Wife to the love triangle between Alicia, her husband Peter (Chris Noth), and her former lover Will (Josh Charles).

And nothing could be further from the truth. The Good Wife's romantic entanglements were fun, but they were secondary to the story of Alicia's journey from political wife to self-determined woman, pushing back against the status quo.

The reason the Alicia-Peter-Will triangle worked so well in spite of its secondary status was that it so closely paralleled the series' core conflict: the clash between who Alicia was and who Alicia could be. This is not to say Alicia was on a continuum, leaving the husband who cheated on her and rocked her marriage with scandal to take up with someone new, who might see her as an equal. No, it's to say that Will represented something else, a life where Alicia could determine her own destiny.

And that was both because of her romantic chemistry with Will (which was palpable) and because of where he worked, the law firm of Lockhart-Gardner, where Alicia got a job in The Good Wife's first episode. The idea that by moving on from Peter, who was a tool of the corrupt system, Alicia could be more like herself — and more like Will, who was constantly trying to change said system — was baked in at the get-go.

Obviously, her relationships with both men changed over the course of The Good Wife's run, as they will in all serialized TV shows. But the central idea of Peter and Will representing different futures for Alicia was always a major part of the show's premise.

The Good Wife structured its relationships differently than most other TV shows did

Compounding the vitality of the triangle was the fact that The Good Wife was somewhat unusual in the way that almost all of its important relationships involved Alicia.

You have to swim out beyond the relationships between Alicia and Will, Alicia and Peter, Alicia and Diane (her boss), Alicia and Kalinda (her former best friend), and Alicia and Cary (her rival turned partner) to find a pairing that doesn't involve her but was immensely important to the show, in Will and Diane (they're the Gardner and Lockhart in Lockhart-Gardner).

All of those characters worked mostly in tandem with Alicia because each one stood in for the various parts of her life she'd shut down in the wake of becoming Peter's wife and a political prop. Kalinda was a friend. Cary was an increasingly friendly rival. Diane was who she might have become, if she hadn't married Peter. And so on.

So The Good Wife wasn't really a show where voids left by departing main characters/actors could be filled simply by shifting focus to supporting characters' relationships to each other, as would happen on most TV shows.

Mad Men is a good example of how a show will occasionally build out its supporting relationships to the degree that the protagonist can remain largely absent for several episodes and not be missed. (On the comedy side, see New Girl.)

Shows like The Good Wife, where the protagonist is at the center of almost every character relationship, can succeed (Breaking Bad is a good example), but they're more difficult to pull off.

When Will left the show in season five and then Kalinda followed in season six (though Kalinda and Alicia hadn't shared a scene together in several seasons at that point), The Good Wife lost two of its main pairings. And that created large holes the show just couldn't fill, no matter how it tried.

Will's death was the show's biggest twist, but it also set a bad precedent

Thus, Will's death, though it was a seismic moment in terms of the show's buzz, ended up paying diminishing returns. Both the event itself (in which he was gunned down in a courtroom) and its aftermath created a spike in discussion around The Good Wife, at a time when it was increasingly a hot series to celebrate and argue about.

So the moment in and of itself was enthralling. It was a great example of how to write off an actor who wants to leave a show (as Charles did), while simultaneously telling an exciting story and giving the other characters something meaningful and fresh to play. The follow-up episode, where various characters began to cope with Will's death, was a thoughtful consideration of grief, if nothing else.

But Will's death also spoke to how The Good Wife increasingly seemed addicted to twists and big moments, sort of Game of Thrones in the courtroom, a tendency that would spiral out of control just a few episodes later, when season six began. And without Will there to represent a kind of life Alicia could lead, the series lost one of its key pillars.

Obviously, The Good Wife was boxed in when it came to solving this problem. Charles wanted to leave the show, and killing off a beloved character is often a great way to create drama (especially on a series like this one, which was thoroughly dedicated to following the journey of its protagonist, instead of a large ensemble). Merely having Will move away, for example, might have kept him out there as a kind of beacon for Alicia to aspire to, but wouldn't have had nearly as much emotional power.

But his death also robbed The Good Wife of something it had constructed very carefully in the five seasons leading up to that point, something it could not easily rebuild. The show may have produced its finest hours in the wake of that big twist, but its fall from those heights was precipitous.