1. Stefan and Elena's Relationship Deepens: Stefan and Elena's relationship could grow stronger as they face new challenges and obstacles. Their love story could be tested by external factors, such as family conflicts or supernatural threats.
2. Damon's Redemption Arc Continues: Damon's journey towards redemption could progress further. He might have to make difficult choices and face his past wrongdoings to become a better person.
3. Klaus' Return: Klaus, the original vampire, could make a comeback and pose a significant threat to the characters. His presence could bring about new conflicts and alliances.
4. Elijah and Hayley's Relationship: The relationship between Elijah and Hayley, a werewolf, could develop. Their connection could bring new dynamics and complications to the storyline.
5. The Werewolf Curse: The werewolf curse and the existence of other supernatural beings could be explored in greater depth. The characters might uncover more about the origins and rules of these supernatural phenomena.
6. Human Perspective: The show could delve into the perspective of human characters who are unaware of the supernatural world. Their interactions with vampires and werewolves could bring about interesting storylines and dilemmas.
7. Mystic Falls High School Life: The characters' lives as high school students could continue to be a part of the story. Balancing their supernatural lives with their human identities could present new challenges.
8. New Villains: The season could introduce new villains, either supernatural or human, who pose a different kind of threat to the characters.
9. Character Growth and Backstories: The show could explore the backstories and motivations of various characters, providing more depth and understanding of their personalities.
10. Unforeseen Consequences: The actions and choices of the characters in previous seasons could lead to unforeseen consequences, setting the stage for new conflicts and alliances.
These are just a few potential storylines that could unfold in the third season of The Vampire Diaries, offering fans a thrilling mix of romance, drama, and supernatural elements.