Basically, Bella realizes that she's pregnant while her and Edward are on their honeymoon. She talks to Carlisle on the phone and he says they should come back. When they return he confirms that Bella is indeed pregnant. THey think she should get an abortion but she can't go through with it. THen the baby is killing her so Edward is forced to bite her. She names the baby Renesme or some shit, her mom and Esme's names put together. As soon as the baby is born everyone falls in love with it and she is immeditaely excepted into the family. Um... she grows really fast and Jake falls in love with her. Well, he imprints on her. Which basically means they are meant to be together forever.
And... I don't blame you for just asking rather than reading it. I read the first two and couldn't take anymore of the terrible writing. But I lliked the story, it's pretty original. So I asked a friend to explain it...
Also, if you've never seen a vampire how do you know they don't sparkle in sunlight? That's the one thing I never got...
Although it isn't a logical idea, you have to admit that no one has ever thought of it before... I give Stephanie credit for at least that...