In the year 2025, global warming has caused the polar ice caps to melt and the sea to rise, flooding large swathes of land on Earth. Richard and Amy Webber, members of environmental pressure group Greenwatch, help children with telepathic skills they hope will eventually enable them to restore the drowned planet's land. They discover that two telepaths, Mai-Li and Ash, show particular promise, with the former able to 'flip', turning physical systems inside out via basic telekinesis.