There came an elastic aftershock of creaks and groans and then, softly softly, a chinking shower of rubbled cement. Leaves calmed and trunks stood serene. Where, not a minute before, there had been a suburb, there was now only woodland standing amid ruins. There is no warning. No chance to prepare. They arrive in the night: thundering up through the ground, transforming streets and towns into shadowy forest. Buildings are destroyed.
When Elsa's father is killed in a tornado, all she wants is to escape. For years she has been haunted by a sight once seen from an aeroplane: a tiny, isolated settlement called Thunderstown. In Thunderstown, they say, the weather can come to life and when Elsa meets Finn Munro, an outcast living in the mountains above the town, she wonders whether she has witnessed just that. For Finn has an incredible secret: He has a thunderstorm inside of him.