Amos the mouse and Boris the whale: a devoted pair of friends with nothing at all in common, except good hearts and a willingness to help their fellow mammal. They meet after Amos sets out to sea in his homemade boat, the Rodent, and soon finds himself in extreme need of rescue. Enter Boris. But there will come a day, long after Boris has gone back to a life of whaling about and Amos has gone back to his life of mousing around, when the tiny mouse must find a way to rescue the great whale.