It is now mid-way through the twelfth year in Grendel’s war with the humans. Grendel thinks that his enemies do define themselves against him, just as the dragon said. He could kill all of Hrothgar’s men in one night, but he restrains himself, realizing that he needs the humans, as well. He asks, “What will we call the Hrothgar-Wrecker when Hrothgar has been wrecked?”
Grendel recognizes that the humans use him to define themselves. But he also realizes that he defines himself through his difference from and rivalry with the humans. Monsters and humans need each other.
Grendel sings, influenced by the language of the Shaper. He thinks he might be crazy but keeps singing. He narrates in third-person how he scares a human out in the wilderness. He has killed his quota of men for the season. Following from his self-imposed quota, Grendel formulates what he calls Grendel’s law: “There is no limit to desire but desire’s needs.”
Grendel is further influenced by the Shaper’s alluring singing. His new understanding of his relationship with the humans moves him to formulate “Grendel’s law”, a further example of his attempt to make sense of the world through theories and reason, just as the humans do.
As Grendel’s stream of consciousness continues to alternate with third-person narration, he thinks of Hrothgar’s queen, Wealtheow, and tries to define her geometrically and physically as a cross-section of time-space.
Grendel’s attempt to see Wealtheow as a cross-section of time-space shows his commitment to rational investigation and theorizing.
Grendel remembers how Wealtheow first appeared, during the second year of his raids. Hrothgar had gathered all of his army to fight a new rival king. Grendel watched the army gather and march, eager for bloodshed.
The prospect of war, which used to disgust Grendel, now excites him in the boredom and isolation of his routine.
Hrothgar met with the other king. Grendel anticipated a battle, but the king asked for a truce and offered Hrothgar gifts. Hrothgar was skeptical, but then the king brought out a beautiful woman, his sister, and offered her in marriage to Hrothgar. Grendel was fascinated by the woman. She caused him pain in the same way that the Shaper’s songs once did.
Wealtheow represents another aspect of human life which Grendel despises but also desires. Like the beauty of the Shaper’s art, Wealtheow’s physical, feminine beauty makes Grendel painfully aware of his own monstrosity and his own inability to ever have companionship with a woman.
All that winter, Grendel refrained from raiding Hart. He spent much time in his cave, thinking of Wealtheow and observing his mindless mother. At times Grendel would go to the meadhall and watch Wealtheow serve all the tables, charming Hrothgar like the Shaper. She softened tempers and mediated arguments, her beauty resolving men’s disputes. She calmed Unferth when other men teased him about having killed his own brother.
Wealtheow’s charming power is again compared to the Shaper—just as the Shaper gave men a history to support them, Wealtheow gives them a new sort of home to bring them together. Grendel is fascinated by her beauty and power. Her kind presence among Hrothgar’s people is in stark contrast to Grendel’s mother’s presence in their cave, where Grendel is essentially alone.
Grendel spent much time pondering the power of Wealtheow’s beauty. He often saw her cry at night, missing her old home. Once that winter, Wealtheow’s brother came to Hart. All the men ate, drank, and listened to the Shaper. Grendel watched through the crack in the wall. The humans were all merry, though Grendel noticed some underlying tension between Hrothgar’s men and Wealtheow’s brother and his men. Back in his cave, Grendel was frustrated by the humans’ merriment. Although he had met the dragon and knew that the world was meaningless, he was tempted by the humans’ arrogant self-importance and happiness. Grendel was tortured by Wealtheow as he once was by the Shaper.
Grendel’s reaction to Wealtheow and to the humans’ merriment is similar to his initial reaction to the Shaper’s false but alluring songs. Having met the dragon, he knows better than the humans and scorns their self-important, ignorant happiness. Still, he envies these very traits. His simultaneous disdain for and jealousy of the humans torments him. Note also how Grendel's sadness and loneliness is somewhat akin to what Wealtheow shares. Grendel defines the men by being an adversary; Wealtheow defines them by being someone who joins men together. Yet this position also makes her lonely.
The next night, Grendel raided the meadhall, killing men on his way to the queen’s bedroom. Finding Wealtheow, he picked up her up and examined her, pulling her legs apart. He resolved to kill her, but then changed his mind, since killing her would be pointless. He let her go, noting that doing so disproved the humans’ theories about him. Grendel ran back to his cave, thinking that he had “cured himself” of his recent melancholy, though part of him was still troubled by Wealtheow’s beauty. He decided to kill himself but then changed his mind.
Grendel takes out his anger by attacking the humans. Picking Wealtheow up and examining her, he literally treats her as an object. But the men also treat her as an object, as a kind of combination of beauty and sex rather than as a person. Grendel congratulates himself on letting Wealtheow live, but the humans certainly don't share his sense that he has disproved their view of him. And Grendel's own thoughts betray his statement that he has "cured himself" of her. Incidentally, the phrase "cure himself" suggests that he sees Wealtheow as the problem, the disease, rather than his own overpowering need for her as the problem. This blaming of women is also a typically masculine thing to do.