In 1982, a car overturns on a remote West Australian road. Nobody is hurt, but the impact is felt for decades. Nicole and Samantha Cooper both remember the summer day when their mother, Tina, lost control of their car - but not in quite the same way. It is only after Tina's death, almost four decades later, that the sisters are forced to reckon with the repercussions of the crash. Nicole, after years of sabotaging her own happiness, seems finally content but still can't get through to her sister. And Samantha is hiding something that might just tear apart the life she's worked so hard to build for herself. The Spill explores the cycles of love, loss and regret that can follow a family through the years - moments of joy, things left unsaid, and things misremembered. Above all, it is a deeply moving portrait of two sisters falling apart and finding a way to fit back together.