Podcast: Sometimes motherhood feels like war, says author Nicola Moriarty

MumsSleepless nights. Toddler tantrums. Porridge in her hair. Frankie needs the support of her online mums' group just to keep her off the gin.Versus Non-MumsLate starts. Early finishes. Endless school plays and sports days. Poppy and Annalise are driven mad by mums enjoying special privileges at work while they pick up the slack. Setting up a Facebook group to vent about smug mummies is just a healthy outlet - right?Equals WarBut as their new group's membership soars, the frustrated women start confronting mums in the real world. Cafes become battlegrounds, playgrounds become warzones and offices have never been more divided.A rivalry that was once harmless fun is about to spiral out of Poppy and Annalise's control.Because one of their members is a wolf in sheep's clothing. And she has an agenda of her own .

Joni, Deb, Eden and Trina try to catch up once a year for a girls' getaway. Careers, husbands and babies have pulled these old high-school friends in different directions, and the closeness they once enjoyed is increasingly elusive. This year, in a bid to revive their intimacy they each share a secret in an anonymous letter. But the revelations are unnerving. Then a fifth letter is discovered, venting long-held grudges and murderous thoughts. But who was the author? And which of the friends should be worried? The Fifth Letter is a searing examination of the bonds of women's friendship groups, the loyalty and honesty they demand, and the pain of ending relationships that once seemed essential but might be outgrown.About the AuthorNicola Moriarty lives in Sydney's northwest with her husband and two small (but remarkably strong-willed) daughters. She is the younger sister of bestselling authors Liane Moriarty and Jaclyn Moriarty. In between various career changes, becoming a mum and studying at Macquarie University, she began to write. Now, she can't seem to stop.