Fans have grown up with Bay (Vanessa Marano) and Daphne (Katie Leclerc) Kennish-Vasquez over the past five seasons of Switched at Birth — from finding out they went home with the wrong biological families at birth, to dating each others' best friends, rebellious streaks and coping with the death of their father Angelo (Gilles Marini). After all of those adventures, the girls will have their biggest one beginning Tuesday when the final season of Switched kicks off.

Even though there's always been plenty of drama to go around, Switched at Birth at its core has been about how these two girls have matured and turned into young women. When the premiere picks up, the girls are in the middle of a life-changing trip to China. A six-week summer sojourn has turned into a year abroad before they're brought home by a mysterious phone call implying that someone back home in Kansas City is in urgent danger.

Aside from the China of it all, the final season of Switched at Birth will also deal with racism on college campuses, tackle mental health and celebrate its 100th episode. TVGuide.com talked to creator Lizzy Weiss about how the girls have changed this season and what fans can expect from the final 10 episodes.

Katie Leclerc and Adam Hagenbuch, <em>Switched at Birth</em>Katie Leclerc and Adam Hagenbuch, Switched at Birth

What have Bay and Daphne learned during their time in China and how are they different from when they left Kansas City?

Lizzy Weiss: Something happens in China that brings the girls together and makes them decide to turn the trip from a five-week summer vacation into a year-long experience. We're going to jump right in in the first minute with that. We're going to throw you in China with our girls and you'll see what happened. You'll see how it changed them.

It's great to have the girls together. It's always fun to have our girls in the same story and experiencing something together, because so often they are off on different stories and we only get to cross them once or twice. We were just really excited to start off the season in this very pure Switched way with our girls off alone in the world without being able to rely on anyone but each other.

How will that improve their relationship?

Weiss: Something does happen that really bonds them. They've gone through incredible stuff together: being each other's other half, each one of them leading the life that the other was supposed to have, Bay taking the fall for Daphne, overlapping love interests, but there is something else that happens which they have never gone through that is the next level of intimacy for them that really bonds them. Then we get to come home with them and see how they bring that experience back with them and try to hold on to it. Sometimes when you go away and then you come back, it kind of vanishes and you have to look at each other to try and remember everything that happened, in a good way.

Switched at Birth's final season will turn the girls into the people they want to be

Since this is the last season, what is the primary goal you want to accomplish with these final 10 episodes?

Weiss: I'm really lucky because we've been on for so many years. We've gotten to do so many incredible things. I definitely wanted to cross the 100-episode mark and we did that. That was definitely a goal all along. Creatively, maybe if we had gone another 10 we would have tried another all-[American Sign Language] episode, but it was really fun every 10 to try something different — from a dance episode to this time we're doing a shift-in-perspective episode to really deal with race relations on campus. Every time we, the writers, sat down in the room, we would get inspired. There's nothing else I was holding in my pocket that I was hoping to do and didn't. The 100[th episode] was a really important mark for all of us.

What are you most excited for fans to see in this final season?

Weiss: Definitely the campus racism story. I'm super passionate about that and I'm so excited to see how people of all different backgrounds respond. We have the 100th episode, which is very touching. Angelo comes back in a special way since he passed away. It's a frenzy putting on a show and we all just sort of stopped and looked around and said, "Hey, we really have come a long way together."

There's just some fun stuff. Episode [3] is a really great Toby/Lily story that I'm excited about. Of course, there's always Carlton, [their son], stuff peppered in. We always come back to diversity and the different types of diversity in this family. I'm excited to see the series finale, of course. It's going to be a lot of tears, but I am excited for everyone, especially for fans that have been there for five years to sort of sit down with some Kleenex and say goodbye. There's stuff all throughout that I think everyone is going to be excited about.

Switched at Birth Season 5 premieres Tuesday, Jan. 31 at 9/8c on Freeform.