Return of el Nina: The fourth season of Offspring follows Nina's pregnancy and relationship with fiery sister Billie.
Mention to Asher Keddie an amusing scene in Offspring - say, the funny yet painful scene in the opening episode of season four when the Proudman family gathers to welcome home from hospital baby Alfie - and the actor bursts into laughter.
''We always come from a position of truth,'' the recently crowned silver Logie winner says. ''If it's funny, terrific; if it's not, the scene becomes moving in a different way and that's OK as well. I'm terrible if I try to be funny. I would not be a good stand-up. It took a while for me to learn that, though.
''Tonally when we first began the show … we were all working a little bit harder, perhaps in the wrong areas, but now because we know the show, the characters, their relationships and the tone of the show, we want to deliver it so it does feel almost effortless.''
Asher Keddie: 'I want Nina and Patrick ... to commit.'
Indeed, one of the qualities of the show is its unpredictability - the way in which the neurotic perceptions of Keddie's protagonist, Nina, can spiral from drama into farce, the short fuse that can detonate whenever her volatile sister, Billie (Kat Stewart), steps into frame and the ever-changing dynamics of her self-possessed parents, Darcy (John Waters) and Geraldine (Linda Cropper).
As well as playing Nina, Keddie has been an integral collaborator on Offspring from the moment the show's creators, Debra Oswald with John Edwards and Imogen Banks, hatched the idea of a contemporary drama built around an obstetrician with a fabulously messy love life.
''One of the most enjoyable parts of shooting the show for the past three years is that I felt really welcomed to collaborate with the writers and offer my voice and opinion, and they respect that the person playing the character might have something interesting to offer as well,'' Keddie says.
''On a working, day-to-day basis the writers are open to discussion with me on an early draft of a script, or if something's not working for me then I'll offer a solution that might work. It's very collaborative in that way.''
The finale of the previous season offered up a tantalising fork-in-the-road scenario for Nina when she discovered she was pregnant to Patrick (Matthew Le Nevez).
After three seasons of a roller-coaster ride through messy relationships and delivering babies for (mostly) happy families-to-be, she's about to join their ranks.
When the question of Nina getting pregnant was up for grabs during the writing of the third season, Keddie says she put herself in the position of viewers.
''I remember asking myself that question: 'Do I want to see her pregnant, having gone through such a big journey with her?' … and the answer that came back to me was I want to see it because I want to see her be challenged by not just fixing everyone else's problems.
''I want to see her look after herself and move towards a very different situation. To me it felt right. It also felt right because I want Nina and Patrick to have to make a big choice and commit to a relationship, one of maturity rather than a ridiculous tug of war that they had going on for so long.
''They clearly wanted to be together, they didn't want to separate, but there had to be a big choice involved and the writers felt that, too.''
The fourth season follows Nina's pregnancy, but how this will shape the show's future - a fifth season will film in the second half of 2013 - remains to be seen.
''I rationalise it this way: it could be an endgame situation … but anything can happen in 24 hours, let alone a nine-month period which we track this fourth season with her pregnancy.
''I certainly don't think we're playing an endgame and I can't wait for the audience to see the latter episodes.''
According to Keddie, the other big theme of the new series is the complex relationship between Nina and Billie. ''At the core, these two sisters are really similar,'' she says.
''They're very sensitive, they're both neurotic, they both struggle with similar things, as different as they seem.
''They both try, they're both active characters who try very hard to get it right. I like that we've gone heavily into exploring that dynamic.''
Offspring returns on Wednesday at 8.30pm on Channel Ten.