Lily Jameshad the “first day from hell” while filmingPam & Tommy.

It’s the first time viewers see the actress' passionate determination brewing under the surface.

(Check out the full scene above.)

“The point of it is to shock and surprise the audience, like, ‘Were you underestimating me?

Well, here we go,'” she tells EW’sThe Awardist.

“It’s such a slam-dunk, mic-drop moment.

It really shifts everything, and I do like how the writers made it like a Trojan horse.

You think of it as one thing, and then it becomes something else.

It’s just such a cool moment.”

That said, filming it first “added an absurd amount of pressure,” James admits.

“I’d only been dressed in the character like three times.

And then suddenly, I was doing this huge monologue.

I was so nervous.

I was just thrown into the deep end, and it was pretty terrifying.

Of course, I was completely paranoid that we didn’t get it.

I didn’t want to f— up.

I didn’t want to get fired on the first day.”

James credits director Craig Gillespie with getting her into the right headspace for the scene.

“And he really lets you play.

By letting you just do take after take and resetting in your own time, it feels more relaxed.

I actually did loads of improvising in the scene, and they didn’t put any of it in.

I was kind of bummed about that, but it turned out great.”

“There’s this new path that Pam is taking withBarb Wire, and everything feels so scary.

“I started to relate and understand it from my own perspective.

It’s like your most authentic voice just comes out of nowhere and these words spill out of you.

And as that’s happening, it becomes really easy.”

“I just think that what she’s saying matters so much,” she says.

Everything in the scene was just exactly what I wanted to be exploring and talking about.

It’s so powerful.”