That sweet enemy

From the book description: Mary Burns is travelling through Europe with her friends when war resumes between Britain and France in 1803 and Napoleon orders the arrest of all British subjects on French territory. Their fate is to be decided by Captain Armand Dufour, who has bitter personal reasons for taking vengeance on the English. He offers safe passes for the whole party ­ on condition that Mary remains behind as his wife. With internment as the alternative, what choice has she? Yet cold, sarcastic and disfigured as he is, she finds herself drawn to the enigmatic Captain. If her situation is so terrible why does she fail to take advantage of the opportunity to escape?