Pub manager James Wannerton develops a strong taste of earwax in his mouth every time he sees a regular called Derek. John, meanwhile, sees words as colours, even though he is blind. Both of these men have a condition called synaesthesia - where senses become inextricably linked - which, for years, cynical scientists have consigned to the same category as seances and spoon-bending. But now it appears we are all synaesthetic to some degree; it could explain how creativity and language evolved. This touching and witty film explores this strange world.