The ' Black Queen' is what Billy calls his shadowy next-door neighbour. She always wears a black cloak & a wide-brimmed black hat. She lurks about her garden alone except for her black cat. Scarily for Billy the Black Queen befriends him & asks him to look after her cat while she's away. Billy can't resist the opportunity to peek inside her house. There are chessboards scattered everywhere. Who is the Black Queen & what sort of game is she playing? Billy thinks he knows...