Beowulf is a brave legendary Geatish warrior who travels to Denmark alongside his band of soldiers, which include his best friend, Wiglaf, in answer to the call of King Hrothgar, who needs a hero to slay a monster called Grendel, a hideously disfigured troll-like creature with superhuman strength, who attacks Hrothgar's mead hall, Heorot, whenever the Danes hold a celebration there, and he was forced to close the hall. Upon arriving, Beowulf immediately becomes attracted to Hrothgar's wife, Queen Wealtheow, who does not love her husband, and also takes interest in him.

Beowulf and his men celebrate in Heorot, in order to lure Grendel out. When the beast does attack, Beowulf attacks him unarmed and naked, determining that since Grendel seems to be immune to mortal weapons and carries no weapons of his own, armour and a sword would be pointless in the fight. Watching his reactions during the melee, Beowulf discovers that Grendel has hypersensitive hearing, which is why he interrupts Hrothgar's celebrations – the noise they make is physically painful to him. Beowulf tears off Grendel's arm, and as thanks for freeing his kingdom from the monster that plagued them for years, Hrothgar gives Beowulf his golden drinking horn, which represents the time Hrothgar slew the mighty dragon Fafnir. Beowulf is soon sent on the journey to defeat the vengeful mother.