§ Of the Darkening of Valinor The Silmarillion

Now Melkor came to Avathar and sought her out; and he put on again the form that he had worn as the tyrant of Utumno: a dark Lord, tall and terrible. In that form he remained ever after. There in the black shadows, beyond the sight even of Manwë in his highest halls, Melkor with Ungoliant plotted his revenge. But when Ungoliant understood the purpose of Melkor, she was torn between lust and great fear; for she was loath to dare the perils of Aman and the power of the dreadful Lords, and she would not stir from her hiding. Therefore Melkor said to her: 'Do as I bid; and if thou hunger still when all is done, then I will give thee whatsoever thy lust may demand. Yea, with both hands.' Lightly he made this vow, as he ever did; and he laughed in his heart. Thus did the great thief set his lure for the lesser.