VERY GOOD
In a nut shell, it's book five in a series of books about a woman who can travel through time.
The first book starts in Scotland after WWII, and this is confusing... ends up @ the Culloden battle (forget what it's called.)
Thats the 1st 2 books,
Outlander and
Dragonfly in Amber. The 3rd is called
Voyager where the main characters move around a bit, and the next few books,
Drums of Autumn, The Fiery Cross and A Breath of Snow and Ashes are set in the American Revolution.
As you may already know, I'm a huge fan of Diana's. She writes very good historical fiction - but I'm warning you, the books have a lot of romance in them.
I have a feeling a girl you know may be trying to convert you - most people who are fans of Jean Auel's are also fans of Diana's
Since the book is #5 in the series, you may want to read them in order - the books are quite long and sub-plots do kinda come back to haunt you.
If you find any books called
Lord John and the Private Matter or similar, they're not related to the series. Lord John shows up half way through the series, so don't read those till you've at least read
Voyager.