Krysten Ritter returns for final time as troubled P.I. 'Jessica Jones'

"Jessica Jones" has come to the end of her Netflix journey.

The series' third and final season, launched Friday, shows what happens when Jessica Jones (Krysten Ritter), a New York City private investigator with unbelievable strength, crosses paths with a highly intelligent psychopath. Jessica and her best friend, Trish (Rachael Taylor), must repair their relationship to be able to combine their skills to stop the deadly threat. The cast also features Carrie-Anne Moss, Eka Darville, Benjamin Walker, Jeremy Bobb, Sarita Choudhury and Rebecca De Mornay.

Executive producer Melissa Rosenberg looks at the three seasons as a full story arc.

"It felt like it would come to an end there, and we were able to find a very satisfying ending for each of the characters," she said.

"It really feels like the three seasons are three acts of the character. In some ways it feels like a 39-hour movie."

In Season 3, Jessica deals with residual effects of the first two seasons. Ritter pointed to a line from the end of the second season that she sees as one of the biggest triggers for the third season.

"We left the second season with this sound bite in Jessica's head from her mother, who told her, 'You are a hero. Hero means just [caring] and doing something about it.' That, I feel, is the conceit of the third season and what we move forward with," Ritter said.

Ritter has appeared on such programs as "Breaking Bad," "Veronica Mars," "The Blacklist," "Gossip Girl" and "Gilmore Girls." She got to delve deep into a twisted mind when she starred in the TV comedy "Don't Trust the B---- in Apartment 23." When Rosenberg cast Ritter in "Jessica Jones" in 2014, she knew the actress would bring "both the hard edge and the vulnerability the role demands."

Playing Jessica was not easy. Ritter would go home after a day of filming drained because the character has been emotionally and physically abused.

"Of course it's been draining," she said. "But what's draining about it is what has made it such a good part. It's what makes it such a good acting job. What is hard about it is what you want in a role."

Rosenberg's plan from the start was to take Jessica on a journey. The scripts were written to have a character being pushed into areas she's never been before.

Jessica never apologized for being tough or sarcastic or brutal. Fans told Ritter that it was that attitude that made the character so appealing. Ritter laughed and said she thinks that people believe that she is cooler than she really is because of the show.

"This show is really personal and has been very personal from the beginning," Ritter said.

"Season 1 was about her past and her tormentor. Season 2 was about reconciling about the loss of her family and dealing with the relationship with her mother. Now Season 3 is about her relationship with her best friend.