Fifty years pass. Hygelac has died in a distant land, leaving Beowulf to reign the Geats. In the fiftieth year of his reign, another monster has the Geats under attack. A slave stole a cup from a fire-breathing dragon's treasure trove. This dragon was guarding the treasure, which was left by an ancient civilization. The last member of the race has a particularly moving speech in which he realizes that life is fleeting, compared to the permanent wealth. Eventually the dragon found the treasure, and he has guarded it for three hundred years. He slept in peace until the slave stole the cup as a plea for mercy from his lord. Now the dragon realizes that something is missing, and he goes on a rampage to find the cup.
Beowulf learns of the threat through the message that one of his mead-halls has been destroyed. The horrible news causes him to wonder if he has done something to upset God. He manages to have a large shield made in preparation for the battle with the dragon. Yet he fully realized that he is not the same young man who saved Heorot, and he has no desire to do battle.
He recalls the sad events of Hygelac's death. Hygelac died in the land of the Frisians, and Beowulf only barely escaped alive. He sailed home, where Hygd offered him the throne. Beowulf refused it in favor of Hygelac's son Heardred. The Swedes, however, betrayed Heardred and killed him, thus leaving Beowulf as the only heir. So Beowulf ruled for fifty years peacefully until the dragon came.
Beowulf and eleven of his thanes march to the cave of the dragon, as the slave who stole the cup shows them the way. As they wait before charging into the cave, Beowulf, his mind heavy with the thought of death, recounts the history of the Geat royal family. Hygelac's brothers accidentally killed each other, leaving their father to die of a broken heart. Then the Swedes came to attack, and Beowulf served Hygelac well. He gained the great sword Naegling in one of the battles with the Swedes, and he has used it since that time. Having fought bravely through his life, he is now ready to face the dragon.
How the world has changed over the fifty years of Beowulf's reign! All the old, great kings of long ago are now dead, as we learn from the tale of Hygelac's death. Instead of peace between the lands, everyone is engaged in a Germanic-world war. All the respect that masters and servants held for each other is now gone, to be replaced by a desire for wealth and freedom from oppression by the higher classes (as seen in the motivation for the cup-stealing). Mead-halls are destroyed, brothers kill each other, and kings live in fear. This is the culmination of the darkness that began shortly after Grendel's defeat.
The narrator reveals the similarity between the mighty Beowulf and the lowly survivor quite powerfully. The survivor speaks hauntingly about the uselessness of wealth when death is so near. After the dragon arrives and attacks, Beowulf is shown, worrying about the usefulness of life when battles and death are waiting. Each man has his own dragon to fight (the monster of greed for the survivor and the actual dragon for Beowulf), even as they wait for death.
A story imagined previously actually occurs, showing the predicting nature of stories. The scenario that Wealhtheow feared for her own sons happened to the Geats. Hygelac's sons are killed not by a brother, but by a brother tribe in the Swedes.
Beowulf is not the warrior he used to be; instead, he resembles the now-dead Hrothgar. Once he needed only his bare hands to defeat an enemy; now he needs a pilfered sword and a large shield. Once he relished a battle; now he wishes he didn't have to fight. Once he knew victory was certain; now the only thing certain is death. The narrator clearly represents the change in men between youth and old age.
Beowulf's pause before attacking is akin to Jesus' speech at the Last Supper. Certainly the settings are similar. Beowulf is surrounded by 12 men, with the slave who stole the cup acting as the betraying Judas (and the destroyer of the kingdom). Beowulf, like Jesus, knows that he will die soon. He passes on the story of his rise to the throne to his disciples, so that they will pass it on in remembrance of him.