The highly acclaimed Amazon series Goliath comes to a close with its fourth and final season, which premieres September 24 on the streaming service. The stakes may be higher than ever as Billy McBride (Billy Bob Thornton, Y: 1883) and his band of highly skilled misfits takes Big Pharma to task in a case whose mystery goes deeper than they could have imagined.

Tough escort-turned-paralegal Brittany Gold (Tania Raymonde) left at the end of the previous season to pursue a new life in Chicago, but she soon returns home to help with the latest fight. Billy and his law partner Patty (Nina Arianda) are embroiled in a battle against opioid manufacturers in San Francisco, thanks to a cushy job with Margolis & True, but their personal demons and the professional danger zones they step into mean that all hands need to be on deck.

Related: Billy Bob Thornton Goliath Interview

Raymonde spoke to Screen Rant about the growth Brittany has experienced over the course of four seasons, and how she really sees Billy when all is said and done.

Tania Raymonde in Goliath

Screen Rant: Watching Brittany grow from being a mess in season 1 and needing a lot of help to having her life together in season 4 has been such a pleasure. Can you talk to us about Brittany's new life in Chicago?

Tania Raymonde: Brittany has, I think, put on her big girl shoes and tried to live a straight life now. I think she's been through a lot; Billy's really helped her and she's helped Billy, and she's trying to do the right thing.

But I think [there] is a part of Brittany that almost wishes that things were back the way they were. In the beginning of this year, she ends up helping Billy on this case again, like old times. It's almost like the two of them are sidekicks investigating this crazy new case. That was really nice, to get back in the saddle with Billy in that way.

She has that soft spot for Billy, but also for Denise (Diana Hopper). She's almost the link between them this season, when there is a vast distance in that relationship. Can you talk about her being almost the third member of that family?

Tania Raymonde: Brittany weirdly - because on paper, she's the last person you'd trust to babysit your kid - becomes the bigger sister and protector of Billy's daughter. She's there as an intermediary when Billy isn't even speaking to his own kid, so Brittany finds herself kind of in the middle as a protective force. Billy can ask her questions about Denise and know that Denise is getting taken care of because Brittany is involved.

But that's sad. I can't imagine what it would be like to be stuck in the middle of a father-daughter relationship like that. It's funny that Billy feels like he can talk to Brittany in a way that he can't with his own daughter.

Billy has all these connections with his team here that feel really intimate and unique in a way that you don't see in other shows, or that you wouldn't expect a man like him to have. How does Brittany view Billy and that connection that they have?

Tania Raymonde: I think it's complex. I think they wear a lot of hats with each other and play different roles. The most important thing is I don't think either one of them judges each other. The most beautiful friendships you have in your life, you know that you can tell this person anything, and you also know that they know what you've done. If you mess up, they're fully aware and you can't hold anything [back from] them, really.

But Billy leans on Brittany the way that he would a mother figure sometimes. So, she has to take care of him like she would a kid - and vice versa. I think Billy's also really been a father to her, so it's sad, in a sense. He's like a surrogate dad, and yet he's got a daughter that he can't even speak to anymore because he feels like he's messed up so bad. And she's stuck in the middle.

Who knows who Brittany's dad is, but he's a surrogate father to her, for sure. It's an interesting relationship.

Looking back on previous seasons, what has been the most important aspect of playing Brittany for you?

Tania Raymonde: Brittany is, first of all, super brave. And I think that's really rad. The only things I've regretted in my life are when I didn't stand up for myself, or I felt like I didn't try something because I was afraid. She's constantly surprised me. She's had a hard life, but she's always made a choice that I didn't expect.

I think I kind of judged her in the beginning. Maybe I had an idea of what I thought an escort would be, which is crazy. And I realized that's the least important thing about her. In fact, she's a human being that's complex and smart - and people are not what they do.

I think it's a nice lesson in not being judgmental. People make mistakes, but there's a person behind it, and you have to take care of that person.

More: The 10 Best Characters In Goliath

Goliath's final season is currently streaming on Amazon Prime Video.