Many twists and turns are expected for season two of the hit time-travel TV series Outlander, but Caitriona Balfe says there's one constant about her role as British war nurse Claire.

"I fight every day and the writers fight every day for a good portrayal of women in the show," Balfe told CBC's Laura Thompson. "I think it's very interesting how you have this strong, central, female character."

Balfe's character, a warm yet practical nurse, started season one married to Frank Randall in the 20th century. She then found herself transported back in time to Scotland, where she marries Highland warrior James Fraser.

The season one finale saw Claire and James sail away on a ship to France in the 18th century, determined to change the course of history. Balfe said fans can expect a lot more to change as well.

"Our characters from season one were always so honest and honourable," she said. "This season they've taken on this task of being duplicitous and underhanded and lying so you see them use a very different side of themselves."

Caitriona Balfe, Outlander

Irish actress Caitriona Balfe says her central character on Outlander feels "timeless". (Jordan Strauss/Invision/The Associated Press)

The Irish actress was cast in the popular Showcase series in 2014 after many of her co-stars had already been preparing for months on location. A whirlwind schedule began immediately following her final audition.

"A week later, I was in Scotland and we started shooting within two weeks later after that," said the 36-year-old former model. "All of the sudden, my Twitter account was exploding, so I kind of knew that there was a fan base, but I didn't realize the magnitude of them."

In the upcoming season, which premieres Sunday in Canada, Claire and James Fraser leap from 18th century Scotland to France with a mission to stop the Jacobite rebellion. New excitement and tension in her romantic relationships are bound to ensue.

"We try to show that no matter what society's norms, the strength and the power of women always shines forth," she said.

Outlander cast

Cast members Tobias Menzies, Caitriona Balfe and Sam Heughan attend the Outlander season two world premiere on April 4, 2016 in New York City. (Robin Marchant/Getty Images)