Love Is Invincible — Barbara Cartland

For the Marquis of Shawforde and Lucille Winterton, it was love instantly and irrevocably. The country-bred beauty was worldly enough however to know that the Marquis's family would never countenance their union... and in fact the Shaws sent Her Majesty's most trusted Secret Agent to prevent it, and he also became deeply involved in a drama of terrible danger. What ensued was a menace of aggressive terror which is circumvented by the invincibility of Love.