It is 2071, 29 years after Earth's Great Climate Catastrophe. Syd, a chemist at a powerful mega-corporation, meets Jake who takes her to a cave that contains a portal to another planet, Cascadia an oceanic world suffering its own climate crisis. Meanwhile on Cascadia, Ruddy, a poet employed by the Ministry of Poetry is pursued by resistance forces of an enslaved minority, the In-Between, who see him as the key to their deliverance. An explosion strands him and an In-Betweener scientist on Earth and the four must join forces to save both planets from their climate crises.