1) The poem begins with the genealogy of the Danish kings, including Hrothgar who builds the hall Heorot. The monster Grendel attacks Heorot, killing Danish warriors.
2) The Geat warrior Beowulf hears of Grendel and decides to help the Danes. At Heorot, Beowulf declares he will kill Grendel. That night, Beowulf fights Grendel and tears his arm off, causing Grendel to flee and die.
3) Beowulf is celebrated as a hero. However, Grendel's mother attacks and kills one of Hrothgar's men. Beowulf dives into a lake and kills Grendel's mother in her l