Grendel a spawn on Cain living in the dark and suffering from pain. In disguise Grendel goes to Herot, which was the golden guest hall. While there he slaughters thirty men. After the loss of the thirty men everyone becomes frighten leaving Herot empty for twelve years. Hearing about the tragic Beowulf of the Geats and fourteen of his men goes to Hrothgar to explain how his cleverness has brought him to save the Danes.
He brags of his accomplishment. Beowulf plea to fight Grendel, without using his sword, because he wants to prove that he is the strongest man. Replying to Beowulfs boast, Hrothgar tells how as a new king, he had assist Beowulfs father and in return Beowulf wanted to repay the favor. Hrothgar describes the terror of Grendels attack on Herot. Unferth, a younger warrior, is furious of Beowulfs bragging and challenges him. Beowulf responds to the challenge by telling how in B recca he fought beast of the sea with his bare sword.
As night falls, Herot empties and Hrothgar wishes Beowulf luck in his battle with Grendel. Grendel leaves quietly from his den to Herot. After killing his first Geats, Grendel finds himself in Beowulfs grip and realizes that he has met his death. Beowulfs men attempt to come to his aid, but find that their weapons are useless, and the battle is between Grendel and Beowulf. Clinched in mortal combat, Beowulf rips off Grendels arm and hangs it from the rafter of Herot. Grendel then escapes to his den.
Warriors return to Herot to observe Grendels solitude and to celebrate the defeat. Beowulf is called once again to rescue the Danes from Grendels mother, who has attacked Herot and carried with Hrothgar closet friend. Beowulf confronts Grendels mother. Neither the sword nor the helmet protects Beowulf as Grendels mother tear and claws at him.
Beowulf ends up on his back where the she-monster dagger would have killed him if he had not worn his mail shirt. Getting fed up with the battle, Beowulf notice a sword, which he uses to decapitate Grendels mother. Beowulf announces his intention to battle the dragon and recover his treasure using shield and sword. The dragons flames melt the iron shield.
Wiglaf, Beowulfs warrior remembers the kindness and treasures his family has given him, comes to assist Beowulf. As Beowulf lies dying, Wiglaf brings the treasure for him to see. Beowulf then passes on the leadership of the Geats to Wiglaf and gives him the golden necklace, his helmet, his mail shirt, and his rings. Beowulf request that the Geats build a funeral pyre so that passing ships could see and remember Beowulf.