Before

20 years after breaking dawn, Renesmee is full grown and happily dating Jacob.

Told from Nessies point of veiw for the first hafe then middle to end told from a new person.
Things change
A new story beigns
A new war might have started
And it all began with the first wolf/vamp hybrid impring
Jacob & Renesmee

Few sceans are more "Mature" but not the whole book.