A girl's departure was a major turning point for Arya Stark and Game of Thrones

As we count down to the Game of Thrones series finale, we're looking back at the most pivotal moments of the show's first seven seasons.

Season 4 of Game of Thrones is full of incredible moments that are iconic as well as pivotal. The season is so full of these moments that it's hard to pick the most pivotal out of all of them… in many ways, a strong case can be made that Season 4, as a whole, is the best season the show has produced. At the very least, it's probably my favorite.

Though it includes the Purple Wedding (bye bye, Joffrey), Tyrion's trial, the Viper vs. the Mountain, the wildlings attacking the Wall, and Tyrion giving a monologue that's actually the thematic spine of the entire saga (the beetle killing speech, do not @ me), Arya Stark (Maisie Williams) was perhaps the highest high point. The way she ends the season is a major turning point for her character, but also for the show's overall story. Arya got accepted to the College of Kill! There will be no feast.

**SPOILER WARNING: From this point on, there will be spoilers here and there for Season 8 of Game of Thrones. If you want to remain unspoiled, catch up before those bells start ringing.**

Arya has had a series of mentors as the show has worn on — some have been benevolent, some nasty, and some a little bit of both. Season 1 saw her training with the legendary First Sword of Braavos, Syrio Forel. Season 2 had her learning from Tywin Lannister (of all people), as well as the Faceless Man known as Jaqen H'ghar. In Season 3, she got some tough lessons from the Brotherhood Without Banners, but ended up in the care of Sandor "The Hound" Clegane.

That's how Arya spends most of Season 4 — traveling, chickening, and arguing with Sandor. They are one of the more enjoyable random pairings the show has given us, and it's one that the series recently revisited in Season 8. Arya and the Hound are both greatly changed when they reunite, and though their dynamic is similar to what it used to be, a girl was not quite the same.

Through her Season 4 journeys with the Hound, Arya comes to believe that she has no family left in Westeros. She's wrong about this, but she doesn't know that yet. Brienne of Tarth offers her a chance for hope, but she doesn't trust her. Arya doesn't trust anyone at this point, really — she trusts the Hound over Brienne, and the two proceed to have a genital-kicking battle royale. The Hound ends up bested.

Instead of staying with him (or killing him), Arya throws some of his own "wisdom" back in his face. She robs him and then just leaves him to die. Her last tenuous connection to the continent has been (for the moment) severed. A girl has no mercy.

It's then that the show gives us a beautiful moment of pure fantasy imagery, Arya riding her white horse across a gorgeous, green plain. (The white horse imagery, it should be noted, would also return in Season 8.) She rides her horse to a set of docks and finds a ship bound for Braavos, a place she'd heard about from both Jaqen and Syrio.

At this point, she'd had an iron coin and the not-so-secret password to gain passage to Braavos for a couple of seasons. Jaqen gave her the coin, and told her the words before they parted: "Valar Morghulis." The ship captain who she first approaches waves her off, but then she produces the coin, and says the words. Immediately, the captain responds. With a bow and a "Valar Dohaeris," he gives Arya Stark a cabin on his ship.

As she sails away, Arya looks back at the shore of Westeros. There are many, many, (seriously, many) complaints that have been made about so many aspects of this series, but you'd be hard pressed to find someone complaining about the consistently brilliant score composed by Ramin Djawadi. His music is an essential part of this moment because when Arya looks back at the land she's leaving behind, his gorgeous theme for the Starks plays with a longing melancholy.

But then Arya turns and runs to the bow of the ship. She's looking ahead now, to the open sea, and she's ready for whatever adventures lie ahead. The score changes to a glorious iteration of the main title theme, and soon Arya, the ship, the music, and the show all proceed into their next phase.

Why is this moment so important? For one thing, it's utterly beautiful. The way it's shot, the writing, the performance from Maisie Williams, and the aforementioned bit of scoring all combine to make it extraordinary.

In terms of the big picture, there are larger ramifications looking in both directions. The moment pays off the previous four seasons for Arya — she's systematically lost her entire family (or so she thinks), but now she's going to the home of her first (and best) mentor, Syrio. It continues the Jaqen storyline, and it also pays off the iron coin he gave her. We also know that a girl has a list of names, and that she's sailing off to a place where assassins are created. She's no pushover at the end of this season, but when she eventually returns? Watch out.

This brings us to Arya's future, and looking to that in a Bran-like trance, we can see how pivotal this moment truly is. She's essentially leaving home and going to the College of Kill, and she's making the choice by herself. Braavos, the House of Black and White, the Waif, and a returning Jaqen are waiting to take away her name, her costume, and even her eyesight for a time. She'll learn the game of faces, sell oysters/clams/cockles, see some outdoor theatre, and truly learn the best of what this world's top killers have to offer. Though she gives up her name for a time, she never fully parts with her trusty blade, Needle. We would have cried if she had.

Holding onto Needle is a sign that a girl cannot stop the fire raging within her huge Stark heart. Eventually, she takes her name back. A girl is Arya Stark of Winterfell, and she decides to go home. She decides to go home, it should definitely be noted, with an entirely new bag of tricks up her sleeve.

Thanks to the lessons learned in Braavos, she is able to finally cross some names off of her list in ways that would make Seneca gasp. (House Frey never had a chance.) The skills she has honed overseas also ended up saving all of Westeros when it came to the threat of the White Walkers, as Arya was able to one-ring the Night King thanks to the stealth and skill that she'd learned. Had she never gone to Braavos, she probably would not have been able to make that last-minute clutch save.

As much as Arya's offing of the Night King is a testament to who she became, it is also a testament to where she began — the courage that she musters to do the deed came from something taught by Syrio, not the Faceless Men. "Not today," gave her the courage, and the training from the Kill College (Killage) gave her the skill (skillage).

In the end, all of those fancy Mission: Impossible face changes and knife swaps aren't the most important thing that happened to Arya once she left for Braavos. Simply put, a girl grew up. The girl who left in Season 4 was not the same person who returned in Season 6.

If Arya had never gotten on that ship, everything on the show would be different. House Frey would still exist, and I don't think that I'm alone in feeling mighty glad to be rid of them, my considerable love for David Bradley aside. The stories of the Hound, Brienne, Podrick, Sansa, Jon, Bran, Littlefinger, and the North, in general, would be greatly changed, and not for the better. Also, it bears repeating — without the grown up Braavosi Kill College dropout Arya Stark, the Night King would have won.

It's a good thing for everybody that a girl got on that ship.