While his followers fell asleep Beowulf laid down awake awaiting Grendel's arrival.
Out from the marsh Grendel went hoping to kill anyone he could trap. He snapped open the door to see sleeping warriors. He grabs the first person that he sees and kills him brutally drinking his blood afterwards
Grendel is caught off guard as he tries to grab Beowulf. He then realizes that he has met his match and tries to run but doesn't make it. Grendel died that night.
Beowulf hangs Grendel's body parts to show that he is defeated. The people gather around to celebrate Grendel's unwilling departure.