“All his court were cast down in slumber, and all the fires faded and were quenched; but the Silmarils in the crown on Morgoth's head blazed forth suddenly with a radiance of white flame; and the burden of that crown and of the jewels bowed down his head, as though the world were set upon it, laden with a weight of care, of fear, and of desire, that even the will of Morgoth could not support. Then Lúthien catching up her winged robe sprang into the air, and her voice came dropping down like rain into pools, profound and dark. She cast her cloak before his eyes, and set upon him a dream, dark as the outer Void where once he walked alone.”
Book:The Silmarillion