Kirby is the first eco-friendly town. Solar-powered Supertrees take in CO2 and breathe out fresh clean air. Everyone is happy until Tobias Devell arrives: he opens a factory that tips chemical waste into the river. Charlie and Molly are ‘Climate Kids’, determined to help the planet. When they see fish dying in the river, they decide to do something about it. They will stop Tobias Devell.