On top of Yester Hill there is a giant tree. The bark of this tree is rotten and is oozing blood. Everyone who tries to go near it, feels a frightening presence.
Sierra wants to help the tree after communicating with it. She offered some of her life force and blood for it.
She wanted to take a piece of its bark in return. The tree retaliates, hoists her up with his vines/roots and continues sapping the life out of her.
Grayson quickly heals her weakened body. Hopefully the party can cut her loose and run.