Moss stars as Detective Robin Griffin in Top of the Lake: China Girl, the second series of the crime drama written by Jane Campion and Gerard Lee.
While we last saw her four years ago in Queenstown, New Zealand, the action has now moved to Sydney, where a body has washed up in a suitcase on Bondi Beach.
Robin is not only trying to solve the case but battling with her own demons and trying to reconnect with Mary, the daughter she gave up for adoption - played by Alice Englert, Campion's own daughter (more of that later).
"I loved playing Robin so much," says Moss. "In a lot of ways she's the biggest departure for me as a character, with the accent and with her job, with everything - she's very different from me.
"So it was really challenging. But I felt like by the end of the first season I got the hang of it, and then we were done.
"So I was a little frustrated because I felt like I'd just figured it out and then we wrapped.
"As an actor, you're always thinking 'I could try to do a little bit better this time and I could fix that bit.' You don't get to do that, hardly ever. So to get to do that is amazing."