Hrothgar, Beowulf, and their men track Grendel's mother to her lair under an eerie lake. Beowulf prepares himself for battle; he is presented with a sword, Hrunting, by a warrior called Unferth, one of the Danes who had most vocally doubted Beowulf's prowess. After stipulating to Hrothgar what should be done in the event of his death, Beowulf then dives into the lake to do battle with Grendel's mother. There, he is swiftly detected and attacked by the monster. Unable to harm Beowulf through his armor, Grendel's mother drags him to the bottom of the lake. There, in a cavern containing her son's body and the remains of many men that the two have killed, Grendel's mother and Beowulf wage a ferocious battle.