Ten years after the virus outbreak, the world is devoured by corrupt plants.
The immune Claire can control mutant plants, but is considered a threat by the leader of the survivor camp.
When her childhood sweetheart Allen is infected with the virus while trying to protect her, Claire uses her own blood to temporarily suppress his mutations.
The night Ellen left the letter and left alone, the thorns showed her the way.
"Find him," the whisper said, "or watch him grow into manure."
Purpose: Mutual redemption