As the shadows lengthen over the June grass, all England is heading for Epsom Downs - high life and low life, society beauties and Whitechapel street girls, bookmakers and gypsies, hawkers and acrobats, punters and thieves. Whole families stream along the Surrey back-roads, towards the greatest race of the year. Hopes are high, nerves are taut, hats are tossed in the air - this is Derby Day. For months people have been waiting and plotting for this day. Even in dark November, when the wind whistles through the foggy London courts, the alehouses and gentlemen's clubs echo to the sound of disputed odds. In Belgrave Square old Mr Gresham is baffled by his tigerish daughter Rebecca, whose intentions he cannot fathom. In the clubs of St James' rakish Mr Happerton plays billiards with his crony Captain Raff, while in darkest Lincolnshire sad Mr Davenant broods over his financial embarrassments and waits for his daughter's new governess. Across the channel the veteran burglar Mr Pardew is packing his bags to return, to the consternation of the stalwart detective Captain McTurk. Everywhere money jingles and plans are laid. Uniting them all is the champion horse Tiberius, on whose performance half a dozen destinies depend.