Nell McPherson is a catastrophe expert, but nothing has prepared her for the impending catastrophe of her mum's plans to merge families with boyfriend, Ted and his annoying daughter, Amelia. As if that's not dire enough, grade six is turning into an emotional obstacle course as Nell moves away from her old spelling bee friends and into some rule-bending with new girl, Plum.When Nell decides to tackle the biggest catastrophe of them all, climate change, and campaigns for grade six to attend the School Strike 4 Climate, old friends and new will come together, and along the way plans to foil the family merge give way to an understanding that it might not be such a disaster after all.