Spoiler alert! The following article includes details of the explosive Episode 9 of "Shogun."

Through eight episodes of FX's "Shogun," Anna Sawai has instilled steely resolve into Lady Mariko, the inscrutable noblewoman maneuvering the ever-evolving political maelstrom of 16th-century feudal Japan.

But this week's ninth episode (now streaming on Hulu) brings peak drama and rare emotion to Mariko, the translator and conduit between her embattled lord Yoshii Toranaga (Hiroyuki Sanada) and marooned Portuguese sailor John Blackthorn (Cosmo Jarvis) in the series based on James Clavell's 1975 novel.

"The women on 'Shogun' show their power in very different ways than the men," says Sawai. "And Mariko is finally able to spread her wings and fully show the strength she has concealed through eight episodes."

The New Zealand-born actress, 31, continues her Hollywood ascent with the breakout role after starring in the Apple TV+ series "Pachinko" and "Monarch: Legacy of Monsters." Sawai talked to USA TODAY about the Lady of Steel picking up arms and (gulp) her death in the penultimate "Shogun" episode.

Sawai gritted through 'Shogun' battle, chipped her tooth

The fireworks begin when Mariko publicly confronts the powerful warlord Ishido Kazunari (Takehiro Hira), alleging he is keeping her and Toranaga's consorts against their will. It's an intense standoff, and Mariko won't back down. She refuses to accept Ishido's stalling, insisting, "I will never be captive or hostage or confined."

"It was very liberating to have her speak out at last," says Sawai. "She's not permitted to speak out against the men."

Forcing Ishido's hand, Mariko and company attempt to make their exit from the castle, but their armed retinue is mowed down by the scheming warlord's soldiers.

The samurai Mariko finally takes up a naginata polearm sword and attacks the surrounding guards. Sawai has shown she can excel at slick action scenes in 2021's "F9: The Fast Saga." But this "Shogun" battle ends when the tearful Mariko collapses after futile swings, gaining the sympathy of the noble onlookers.

"It was intense, like I needed to just bite these men and make my statement: that Mariko was not afraid and she'd had enough," says Sawai, who ground her teeth intently while filming the melee. "I was putting so much power into that scene I chipped my front tooth. I noticed the next day looking in the mirror brushing my teeth and was like, 'Wow.'"

Mariko puts her eternal soul on the line in the ultimate gamble

In protest of Ishido's gilded imprisonment, Mariko vows to commit ritualistic suicide. A devout Catholic, she's willing to go through with her plan even when the appointed second, whose job it is to finish the honorable act, fails to show up. Mariko pulls the always-present wooden cross off her neck and is ready to face eternal damnation for ending her own life.

While she planned to sacrifice herself to serve Lord Toranaga, "she didn't think that she would have to go so strongly against her own strong religious beliefs," says Sawai.

Blackthorne startingly steps up to be the second, and stands ready to kill the woman he loves to essentially save her soul. "Mariko understands that it's a huge gesture of love and care from Blackthorne," says Sawai.

But Ishido ends the deadly drama by entering in the final moment to smugly drop passes to exit the castle. Mariko wins that battle over Ishido and her passion for Blackthorne is renewed.

Yes, Mariko and Blackthorne 'pillow' for real

After that emotional drama, Blackthorne enters Mariko's chambers for a passionate candlelit tryst.

"That's the first time we really see them together, and it's so well deserved," says Sawai. "We wanted the audience to see this too. And I'm so happy that we did it."

Viewers will recall that in Episode 4, Mariko and Blackthrone appeared to "pillow," the "Shogun" euphemism for having sex. But the married Mariko calmly insisted the next morning that the dark encounter was actually with a courtesan.

"Obviously she had to hide it," says Sawai. "So the best way to keep a secret is to literally keep it secret from the person that was also there." The new expression of love is short-lived. Ishido sends assassins to kidnap Mariko, breaking the couple's slumber and leading to a tragic end.

Does Mariko die in 'Shogun' Episode 9?

Trapped in a storeroom with assassins outside, Mariko vows again that she will never be taken hostage or captive. As the soldiers blow out the door, she blocks the entrance and absorbs the explosion before Blackthorne can stop her.

If Mariko can't have her freedom, she knows her death will send a powerful statement and cause a serious public backlash against Ishido. "There's no hesitation or fear in dying; it's what she has to do," says Sawai. "She understands what kind of message her death will send."

While Mariko dies before next week's "Shogun" finale, the pivotal character's impact will be profoundly felt, especially by the ever-plotting survivalist Blackthorne.

"Blackthorne has been all about doing anything to live a long life and doesn't understand that your death can mean something, that you can die for a much greater cause," says Sawai. "I'm excited to see the ripples of this power in the last episode."