One of the most important scenes in all of "Game of Thrones" came on its penultimate episode, "The Bells," when Daenerys Targaryen sat atop Drogon and made the choice to slaughter innocent people by the thousands. This moment contained no dialogue. No explanation of her choice was provided beyond actress Emilia Clarke's contorted expression of anger and resolve.

But now the episode's script is available to read at the Writers Guild Foundation Shavelson-Webb Library in Los Angeles, and it helps further explain this pivotal choice made by the Mother of Dragons.

"Dany sees all the people below, like little ants," the script says. "Lannister red, intermingled with fleeing civilians. She has won."

Read more: The 'Game of Thrones' season 8 scripts show significant scenes cut from the last episodes

Dany atop Drogon on "The Bells." HBO

"But she sees the Red Keep," the script continues. "The castle that her family built, that belongs to her. Occupied by the False Queen. She has come so far and she will go further."

Then, showrunners David Benioff and D.B. Weiss (the writers credited for "The Bells"), reference the final line of a Robert Frost poem: "Oh, blood will out. It cannot be contained. Drogon takes to the sky."

'The Flood' is a Robert Frost poem about the inevitability of bloodshed

The "oh, blood will out" phrase comes from the final line of Frost's poem titled "The Flood." The poem is about the inevitable release (or flood) of blood which will flow regardless of how one tries to dam it back.

Daenerys Targaryen looking at the Iron Throne on "Game of Thrones" season eight, episode six. Helen Sloan/HBO

Here's is the full poem, which was published in Frost's 1928 book of poetry titled "West-Running Brook."

Blood has been harder to dam back than water.

Just when we think we have it impounded safe

Behind new barrier walls (and let it chafe!),

It breaks away in some new kind of slaughter. We choose to say it is let loose by the devil;

But power of blood itself releases blood.

It goes by might of being such a flood

Held high at so unnatural a level. It will have outlet, brave and not so brave.

weapons of war and implements of peace

Are but the points at which it finds release. And now it is once more the tidal wave

That when it has swept by leaves summits stained. Oh, blood will out. It cannot be contained.

How the poem further explains the tragic and violent inevitability of Dany's arc on 'Game of Thrones'

As we wrote after the "Game of Thrones" series finale, when the murder of Daenerys was revealed as the conclusion of her tragic arc, the story of the Mother of Dragons seems to be an attempt at showing the inherent immorality of war.

Dany's dragons were the Westerosi equivalent of nuclear weapons. HBO

Dany was a hugely sympathetic character, and she primarily targeted her bloody form of vengeance on people (usually men) who had done awful things first.

But the moment Dany decided to pursue her claim to the Iron Throne, she set herself on a path that was leading to warfare and, by proxy, the deaths of innocents. Author George R.R. Martin has spoken at length about how his story in "A Song of Ice and Fire" is meant to show the real horrors of war on both sides of a battlefield.

Read more: Daenerys Targaryen's downfall on 'Game of Thrones' aligns brilliantly with George R.R. Martin's beliefs about the troubling morals of war

Even if one of the leaders, like Daenerys, has a just cause and good intentions, any war is eventually going to lead to the suffering of the country's people — not just its soldiers. "The Flood" also touches upon this idea.

"Weapons of war and implements of peace are but the points at which it finds release," Frost said.

The moment before Dany took off of Drogon's back to burn down the city of KIng's Landing. HBO

Dany tried to avoid the deaths of innocents for years as she made her way towards Westeros and her ultimate goal of the Iron Throne. But in the end, and after she was pushed into isolation and paranoia, her efforts to dam the blood were futile.

"Taking human life should always be a very serious thing [...] you see this same moral struggle all through history," Martin said in a 2014 interview with Rolling Stone. "It's always the question, when you're at war, do you do whatever it takes to win, or do you actually maintain your own moral standard and ideals?"

Once she decided the Iron Throne was hers by right, Dany made the choice of violence. But it took until that moment she was seated above King's Landing for the blood to flow without reserve.

Read more: Emilia Clarke tried to warn fans last year about Daenerys' final season arc on 'Game of Thrones'

Dany's final moments on the show portrayed her as a zealot. HBO

Many people will still take issue with the execution of Dany's arc throughout the final six episodes, and with the oversimplification of this thesis about war and violence. It also remains baffling that Dany made her choice to burn King's Landing after hearing the bells of surrender. She wasn't compromising her previously established moral lines in order to win — she had already won.

The way the scene itself played on screen left most viewers confused about Dany's intentions, even if Emilia Clarke did her best to convey the Mother of Dragons' choice with nothing but a look.

Now at least the script reveals more for fans to chew on. Fans can read all six "Game of Thrones" season eight scripts the the Writers Guild Foundation Shavelson-Webb Library in Los Angeles.