Water...
Earth...
Fire...
Air...

The spirit of Darkness has been resealed thanks to Avatar Korra and her friends, and the world was once more left to its peace. Or so, that was what everyone thought... Vaatu broke off a piece of himself and allowed it to be sealed up, before fleeing in his weakened state to a vessel. This vessel was none other than the unknowing Jinora, Tenzen's oldest, and brightest daughter. She had such a strong affinity for spirits, so much so that hers and that of Vaatu's melded together perfectly.
Years went on by, no one suspecting the seemingly normal Jinora of harboring such a being inside of her. With her brains and reputation of having helped the Avatar, the master of all four elements, to 'seal' away the spirit of darkness, she quickly rose up the political pole to reach the role of President. Jinora was a perfect President, nothing tarnishing her record, constantly making the people happy. One day she and Avatar Korra traveled away on a business trip. But the trip went sour, and when Jinora returned to Republic city, beaten and bruised, she told them the sad words.
"People of Republic City... The Avatar has been slain. We had been ambushed, we both fought valiantly. As her last living action as Korra, she saved my life. The ones attacking us were evil spirits, and I fear they may of come in contact with Vaatu. I fear that they may be hunting for the new avatar, to end its cycle for once and for all. We must find the new avatar to protect them from any further harm!"