One

Maia Castello makes the biggest mistake of her entire life/existence/whatever you want to call it. Seven months are spent lying to her siblings and parents, hiding from the world, and forcing herself to stay away from Forks.
Sam, Leah's ex-ex-boyfriend, comes to Forks for the first time. And he decides to stay after falling in love with Leah... again.
When someone asks you, "Are you sure about the person you love?"
The answer should always be "Positive."