Grendel is born a monster, and he spends his early life feeding on cattle and other animals. He watches in fascination as Hrothgar becomes king and builds his empire. Although Grendel is put off by men's wasteful ways, he is also fascinated by their lives and spies on their meadhall. Only after Hrothgar's men repeatedly attack Grendel does he make war on them, continuing for 12 years until a visiting hero from another country kills him.
Hrothgar becomes a king by making war and establishing treaties with neighboring kings. He and young Grendel meet one day when Grendel is stuck in a tree. Perceiving Grendel as a fungus or evil spirit, Hrothgar throws his battle-ax at Grendel, and their lifelong struggle begins. Hrothgar and his men come to live in terror of Grendel's late-night raids.
Grendel's mother, pale, slightly glowing, and fearful, lives in a dank cave with Grendel. She smothers her son in her attempts to comfort and control him. When Grendel gets stuck in a tree for many long hours and is attacked by Hrothgar and his men, she rescues him, knocking down trees with her strength. As Grendel nears his fateful encounter with the stranger who will bring Grendel's death, Grendel's mother senses the threat and conveys a warning message to Grendel telepathically. However, on his last night before the fateful battle, she does not try to stop him from leaving their cave.
When Grendel is frustrated by men's wasteful, violent ways and unfriendliness toward him, he questions the meaning of existence; the dragon offers him advice and a worldview both nihilistic and practical, telling Grendel nothing he does matters in the grand scheme of the universe. Grendel becomes permeated with the dragon's view of reality and energy, feeling it inside, and even smelling it at times.