Chyler Leigh and Evan Williams say Kat and Elliot, the characters they play on the romantic time-travel drama, The Way Home, love each other deeply, even though extraordinary circumstances keep driving them apart.

Elliot is Kat's childhood best friend, who as an adult looked after her mother Del (Andie MacDowell) when Kat moved away to marry Brady (Al Mukadam) and raise their daughter, Alice (Sadie Laflamme-Snow).

When Kat and Brady divorce, she and Alice move back in with Del and start spending time with Elliot.

Alice's dysfunctional family starts to make more sense when she discovers a portal to the 1990s via a magical pond, and then meets young-adult versions of Kat (Alex Hook), Brady and Elliot (David Webster).

Elliot, now a science teacher, keeps the women's secrets.

"They have so much history, and there is so much that made them who they are. They went through these really really powerful, traumatic experiences together, and then they were separated because Kat leaves town and Elliot stays," Leigh told UPI in a recent Zoom interview.

The actress, also known for her roles in Grey's Anatomy and Supergirl, described the relationship as even more mature and realistic in Season 2.

"I was going to say 'dirty,' but it's spicy, very spicy," she said with a laugh. "It doesn't mean it has to be tragic and terrible, but it doesn't mean it is going to be easy. A relationship is always going to evolve and change and have its patterns and its waves and its ups and downs."

Degrassi and Versailles alum Williams called what Elliot and Kat have "a long-standing love."

"We get to see in Season 1 that Elliot has pined for Kat pretty much his entire life. So, it's not something that is come by in a small way," he said.

"It is earned and, yet, it's also the sort of realistic storytelling we are doing in the show that it's not as simple as they hook up and walk off into the sunset -- because there is going to be a sunrise. That is the nature of time," Williams said.

While many fans have been rooting for Kat and Elliot, others have worried that Kat is more obsessed with the past than building a new life with him.

Williams acknowledged that a lot of the fan reaction he heard in Season 1 amounted to "Poor Elliot!"

"He's always going to be there -- dependable. I think, in a way, that archetype ran its course within Elliot in Season 1, culminating in him deciding he needed to stand up for himself and start living his own life," the actor added.

"In Season 2, we see the mechanics of that reality as it plays out. It might not be as simple a choice to decide to prioritize yourself because then you have to know who you are."

Leigh said Kat loves Elliot all the more because he always has been so protective of her daughter and mother.

"That is a huge part of it and she also comes to understand this wasn't any easy thing that he has gone through as well, especially at the end of Season 1," she said.

That's when Elliot told Kat he didn't think it was the right time for them to settle down.

Kat respected his decision, Leigh said, adding she understood he needed to figure out what was best for him.

"Sometimes, you really have to protect yourself," Leigh said.

"In that scene when they do break apart, it's bittersweet because she also has to kind of understand and say, 'You have sacrificed essentially your entire life for this family.' She is always going to have an appreciation and a love for him for that, and particularly because of how much he cares for and watches over Alice."

The real-life mother of three said it was easy to relate to Kat because she, too, values people who respect and care for her kids.

"What's not to love about that?" Leigh said.

Kat and Alice may be careful not to disturb the space-time continuum, but their very presence in the past has unpredictable ramifications and "they're going to mess it up no matter what," Leigh said.

"Between the two of them, they are both such headstrong characters who just like to turn stuff up. They are there for such similar reasons, but also for Alice, it has now become such a huge part of her life," Leigh said.

"When she goes back to 1999 to 2000 and she is learning all these things, she is connected with these people in her present-day life that she never imagined she would have that connection with. There is a part of her where it's like that is where her heart is."

But throughout Season 2, it is revealed there is a lot about the past about which Kat and Elliot don't want Alice to find out.

"It digs up and unearths a whole other set of traumas for her to understand -- even how she came about," Leigh said about her on-screen daughter.

"You also never know what time you are going to pop up in, so our characters are constantly concerned with 'When does this happen?' 'Has she gone there?' 'Does she know about this?'"

Williams said two main reasons exist why Kat and Elliot don't want Alice digging too deeply into the past.

"Where is that line between trying to protect somebody and also being selfish because you don't want their perception of you to change?" he added. "A lot of that is challenged in this season."

Like any good sci-fi show, there has to be clear rules and consequences.

"There has always been a through-line -- especially in Season 1 -- where we say what has happened will always happen," Williams said.

"We know we have to have rules. It can't be all willy-nilly or else it all falls apart," he added.

"At the same time we know that's true, our characters are just discovering this whole time-travel mechanism and it's not a given that their understanding of the rules is accurate."