Lucy Lawless, with hits like “Xena: Warrior Princess,” “Battlestar Galactica” and “Ash vs Evil Dead,” knows all about long runs but she remains surprised by the enduring popularity of her New Zealand murder mystery “My Life Is Murder” whose fourth season kicks off tonight on Acorn TV.

Lawless, 56, stars as former detective Alexa Crowe who is paged weekly to consult with the police on a seemingly never-ending series of puzzling homicides.

“I’ll joke that I’m in the Miss Marple phase of my career,” Lawless said in a phone interview.

Involved from the start in creating the character, she specifically wanted a show that was, “something kind of wholesome and not offer sex and violence. Just for a change. Because the world seemed dark.

“We were just making it to fill our own hearts. So it’s a great surprise that the rest of the world is really enjoying it too. I’m delighted and very grateful.”

In addition to its crime solving, “Murder” offers scenic vistas of Auckland and cozy happenings as Alexa bakes and delivers bread to Reuben’s Café (“That really exists at the base of the Auckland Harbor Bridge”), comforts her scene-stealing cat and mentors her assistant Madison (Ebony Vagulans), a former hacker.

Alexa, Lawless said, “has a lot of me. It’s the one that is closest to me. In all my career it’s the only one I’ve done with my own accent.

“The baking was in the DNA of the character from the very beginning.”

Which is very much like Lawless. “I do bake — I’m a gluten-free person – and my husband is a mad chef. So the kitchen is his domain. But the reason it’s in the show is because it is so fundamental to human existence, cooking.”

Each season offers new ripples in Alexa’s life. “She has changed because she was very reluctant to let Madison into her life. And that switched around whereby she was really disappointed when Madison planned to go out on her own and get her own flat.

“You don’t want,” Lawless knows, “your main character to change too much. Because people want to know what they’re getting every week. There’s a comfort factor in that.

“They want to know that the little ragtag family is intact and that you’re going to solve the crime at the end of the day. And it’s going to be a loving jewel box of a show with great coats, a lot of color, a bit of armchair tourism.

“You know, the feeling of the world being set right at the end. I think we’re all a little bit hungry for all’s being right in the world.”

“My Life Is Murder” streams 2 of 8 episodes tonight on Acorn TV.