In eighteenth century France, Charles Macdonald, badly in debt, has been given a choice by his parents The Bastille, or a forced marriage to his wealthy cousin He chooses marriage, much to the dismay of his mistress Louise, who schemes to dispose of her rival, but when his wife disappears, Charles realises that he loves her and his love is so passionate that he will risk his own life to save her from a place that no one has ever survived