You say the ring is dangerous, far more dangerous than I guess. In what way?' 'In many ways,' answered the wizard. It is far more powerful than I ever dared to think at first, so powerful that in the end it would utterly overcome anyone of mortal race who possessed it. It would possess him.
from the book "The Lord of the Rings" by J.R.R. Tolkien (John Ronald Reuel Tolkien)