Oh oh oh, I have an idea!
A young lord is hunting in the woods one morning with his companions. They attack a boar, and in the confusion his horse is spooked and bolts away into the trees. The lord tries desperately to control the creature, but he falls from it's back in a patch of thick bracken and is knocked unconscious. He wakes a few moments later to find a strange ethereal woman kneeling beside him. He is dizzy and confused from the fall, but manages to stay awake long enough to hear her name. However, when the calls of his friends begin echoing through the trees, the woman vanishes.
Days later, the lord goes in search of the local wisewoman. He describes the woman to her and learns that she is not a human, but a strange wild spirit that inhabits the forest. He vows to go in search of her, but the wisewoman warns him of the terrible dangers that lurk in the depths of the forests. He ignores the warnings and goes in search of the woman anyway.
He wanders in the forest for days and is soon lost in it's labyrinthine depths. One night, he stumbles upon a cave and takes shelter there. However, some terrible magic is at work and as he dreams his spirit is separated from his body and he is left as a voiceless ghost. Terrified, he flees back to his home, but no-one can see him. Distraught, he returns to the forest to live out his eternity alone and friendless. However, as he enters the trees, the woman appears and takes his hand. Together, they disappear into the depths of the forest and are never seen again.