Silmarillion Blues : Quenta Silmarillion : VIII. Of the Darkening of Valinor
For a time Melkor avoids those hunting him, still empowered with the ability to change shape or pass unseen. Meanwhile, Ungoliant, a creature of whom her origins are wondered at by even the Eldar, made her home within Avathar, taking on the form of a giant spider, and consuming any Light that fell within her grasp and spinning it out into shadowy webs. Ungoliant is the progenitor of the Spiders we meet throughout The Hobbit and The Lord of the Rings , Shelob and her ilk, dark creatures in spider form that are burned by blessed Light. Melkor seeks her out, taking on his guise of a Dark Lord he bore in Utumno, a form in which he remains, and strikes a deal. "Do as I bid; and if thou hunger still when all is done, then I will give thee whatsoever thy lust may demand." Under a cloak of darkness woven by Ungoliant, Melkor strikes at Valinor in the midst of a celebration of thanks giving and forgiveness. Fëanor comes in simple presentation, and reconciles with Fingolfin bef