Tiddler is always fidgeting. He wriggles and squiggles, and darts and giggles, until his mother says to him, ‘Go out and swim until you are tired, but watch out for the Big Fish’. So Tiddler swims out into the deep sea where he meets limpets and jellyfish, a starfish and a crab. He goes further still, until he comes to a big, dark cave...