They are betrothed yet they have never met before. By day, Sophia has successfully convinced her aunt and therefore, her fiance, Giles, of her sickly, delicately weak health yet at night, she transforms into a seductive beauty who lures man into her traps before she steals from them. Giles isn't interested in meeting his future wife but he's definitely keen to capture the seductive thief.
In terms of storyline, I like 'Brazen Angel' more than 'Brazen Heiress'. There isn't any disappointments in this book although there isn't any surprises at the same time. Towards the end of the book, we are being introduced to Lily and Webb (main characters of 'Brazen Heiress', the second book), giving us an insight of how Lily's "obsession" of Webb begins (it looks like an obsession in this first book). I still like 'Brazen Temptress' most, that's the final book in the Brazen series and perhaps for this reason alone, I'd still suggest you to consider picking up the two earlier books to complete the whole series.