Beatrice and Sebastian, who were childhood sweethearts, are thrown into a marriage upon the return of Beatrice's brother who has been gone for years. Upon John's arrival he discovers that his sister Beatrice is recently widowed & assumes that his longtime friend Sebastian was the one that she had wed & was now dead. He assumed this because when they were all younger Sebastian & Beatrice had promised themselves to each other & John was there as a witness & back in these days a promise could not easily be broken. While John was away Beatrice had married another man who had just recently died. John having remembered the promise had assumed that his sister was now married to his friend & he reminds them of their promise to one another. Although they don't wish to be tied to one another neither one of them wants to break their word. By law that promise made them already married.
You'll have to read the book to see what happens.
I'm not big on European romances, which may be the reason that I didn't care for this book more then I did but nonetheless it was for the most part a good read. It was a very typical romance though where both love each other but neither of them tells the other so they both believe the romance is one sided. I'm bored with that story line. It seems like it's that way in 90% of the romance books I read but oh well, it was good enough. I wondered throughout the entire book how Beatrice's first husband died but it was never revealed. If you like the Lords & Ladies book you'll probably like this but if your preference is American romances you may want to skip this one.