The tree of life is dying, the world is burning, and the witch has been released. Please, any help needed.

After the party arrived, they set out towards a large tower in the distance. After being ambushed by elves, they eliminated all of them. After arriving at the tower, they found out that the witch didn't live their. Moving on, they found a keep with dead bodies scattered around. Finding the witch their, they killed the witch and left to get paid.