Beowulf out of anger leaped into the lake searching for Grendel's mama.
Grendel's mama entered him into her world, clutching him but not hurting him. The fight brought other monsters swimming to watch.
Grendel's mama had him down battling, scratching, clawing, and trying to rip him apart but despite her efforts that didn't work.
Beowulf had spotted a sword hammered on the wall and took advantage, and with all his strength he lifted it above his head and struck her in the neck and cut it through ,as her body fell lifeless to the floor.
Once the battle was over, Beowulf spotted Grendel's lifeless body in the corner and cut his head off to take back to the Danes.
Beowulf entered the mead hall with pure joy to present Grendel's head to Hrothgar to show his bravery.