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Ungoliant aided the evil Vala Melkor in his attack upon the Two Trees of Valinor, draining them of their sap after Melkor had injured them, extinguishing the source of light for the world. She also consumed the reserves of light from the wells of Varda. Afterward the light of the trees persisted only within the Silmarils of Fëanor. Ungoliant helped Melkor evade the Valar by shrouding them both in her impenetrable darkness, causing blindness and confusion amongst the hosts of the Valar that attempted to intercept them.
Melkor had promised Ungoliant that he would yield anything she wished in return for her aid, but betrayed this promise by attempting to withhold the Silmarils from her. This angered Ungoliant, who, having grown immensely powerful from ingesting the life force of the Two Trees, trapped Melkor in her webs. At this point he gave out a cry of such fear and intensity that it was heard in the depths of Angband, and the Balrogs rushed to the aid of their master, scourging Ungoliant with their whips of flame.
Ungoliant fled to the Ered Gorgoroth in Beleriand. At some point she gave birth to Giant Spiders, including the character Shelob in The Lord of the Rings. In The Silmarillion, it is stated that when she went into hiding, and her hunger was such that she would mate with spiders only to devour them later, with her offspring to be used as food once they were fully grown. Few of her off-spring survived, and Ungoliant herself is believed to have eventually died of starvation. Some even believe that her hungry hunger grew so ravenous, that she devoured herself in despair. As a Maiar, however, Ungoliant's spirit is much like Sauron's; she can never truly die, though few in Middle-Earth would understand such a concept.
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