Georgette Heyer wrote very good period romances for light reading, but when she got her teeth into a mystery novel, she was terrific.  Unlike modern writers, Heyer did not need the use of blood and gore graphically depicted.  Instead she used subtle word pictures and managed to keep the reader enthralled to the very end of the book.  The style is not unlike Agatha Christie but is still uniquely Georgette Heyer.  Well worth reading