The Virgin and the Unicorn — Joan Smith

Miranda Vale had learned that Lord Rotham was a rake, when her sister's heart was broken. But Miranda couldn't resist being charmed by the man, who had such courage and daring. She and Rotham's brother, Pavel, got caught up in the adventure Rotham was involved in. But Miranda insisted on protecting herself, even as Rotham was reevaluating his escapades -- and his heart. Regency Romance by Joan Smith; originally published by Fawcett Crest