Part 1

Damon Salvatore begrudgingly accepts a request from his friend Alaric to watch over someone important to him, Emma Peters, who just moved back to Mystic Falls with her older sister.
It doesn't take Damon very long to realize there is more to this fireball of a personality than meets the eye; but that means that Klaus Mikealson starts to realize there is something special about her too.

Season 3 of TVD with appearances by Dean Winchester and mentions of Sam Winchester.