Answer:
The battle against Grendel when Grendel loses his arm
Step-by-step explanation:
The story begins with Hrothgar, king of the Danes, who built the great hall Heorot, where he and his warriors celebrate their feats. Grendel, a troll-like monster, can´t stand the sounds of joy, so starts attacking the hall, and killing many of Hrothgar's warriors. For this reason, Hrothgar and his people abandon Heorot. This is where Beowulf comes in, a hero of the Geats, who hears about Hrothgar's troubles, and leaves his homeland to help Hrothgar. He and his men spend the night in Heorot. When Grendel enters the hall, Beowulf fights him barehanded, and battle violently. Beowulf's men try to help, however their swords can not pierce Grendel's skin. After battling for some time, finally Beowulf tears Grendel's arm from his body at shoulder´s length, and Grendel flees to his home where he dies. Beowulf then displays Grendel's arm for everyone to see, which would fuel Grendel's mother desire for revenge. We can say this is the climax of the first section as it works as the turning point for the story, also it creates the highest tension and works as a trigger for upcoming events. In this point of the story the Protagonist (Beowulf) and the Antagonist (Grendel) stand against each other in a conflict that divides them.