Milly (Toni Collette) is the woman who has everything: a successful career, a rock-star husband, and two beautiful children. Her best friend is Jess (Drew Barrymore), who works in a community garden, lives in a boathouse with her boyfriend Jago, and desperately wants a baby. Friends since childhood, Jess and Milly can't remember a time when they didn't share everything - secrets, clothes, even boyfriends. Their differences act as the glue binding them together. That is, until Milly is hit with the life-changing news that she has breast cancer, and needs Jess's support more than ever. As Jess tries to balance her own life, as well as being there for Milly, it's only a matter of time before the pressure on their bond takes its toll.