In a world of shadows, joyful colours are an act of heroism. Modern tales are filled with clowns who invoke fear not laughter: painted grins covering fanged maws; baggy costumes concealing unspeakable horrors; malevolent parodies of nature. But the tools of a clown work for good as well as ill: only a trickster could tweak a monster's nose; make-up is war paint for the modern age; the devil cannot tempt a happy soul. What...