Georgette Heyer is the queen of historical fiction, but with DEVIL'S CUB she surpasses even herself. It is the most romantic, dramatic, heartstoppingly funny, witty and sharp book she has ever written. In Dominic, the wild, surly Marquis of Vidal, Heyer has created a petulant boy whose dark and dangerous exploits serve to hide a more passionate, loving interior. It is Mary Challoner who makes the book - she is quite simply Heyer's greatest heroine. Pretty, sharp, funny, calm, and with a great sense of humour, she avoids prudery and it's easy to see why Vidal falls for her so hard.
Read it, and don't listen to the snobbish faux intellectuals who'd have you believe Georgette Heyer is fluffy and insubstantial - at her best, she comes close to rivalling Jane Austen.