Beowulf dives into the mere wearing his mail-shirt and carrying Hrunting in its scabbard. Deep in the lake, the mother grasps him tightly with her claws so that he cannot draw his sword. The mail-shirt protects him even though various water-beasts thrust at him as the mother carries Beowulf to an underwater cave, which is dry and lighted by "glaring flames" (1517). Once there, Beowulf manages to mount an attack, but Hrunting is ineffective against the ogre's tough hide. Beowulf then tries to wrestle her, but he fails to gain the kind of death grip that defeated Grendel.
Although she is knocked down, the mother immediately counters Beowulf's attack and soon is sitting on him. She pulls her knife, but it cannot pierce his mail-shirt. Again on his feet, Beowulf spots a huge sword made by giants. Although he can barely lift it, he manages a mighty blow that severs the mother's spine at the neck, killing her. A blessed light suddenly illuminates the cavern, revealing Grendel's corpse. Beowulf lops off the head to replace the trophy of the claw that the mother retrieved.
Amazingly, the giant sword melts except for the hilt, which Beowulf carries along with Grendel's head as he returns to the surface of the mere. Only his Geats await him. Thinking him dead, Hrothgar and the Danes have returned to Heorot.
Beowulf is resolute, and his courage is never in question. Having no sure knowledge of what he will find, he dives into the mere dressed for battle. Scholars disagree about the meaning of the line indicating that Beowulf swam down "most of the day before he found bottom" (1496). As Chickering points out in a thorough consideration of the scholarship of the section (pp. 337-341), the lines from the Anglo-Saxon literally are translated, "[T]hen it was the time of [a] day before he could find the bottom" (1495-96). One way of looking at this is that it is simply daytime, daylight, when he approaches the bottom of the lake and encounters Grendel's mother. (Readers should beware of worrying overmuch about the literal, realistic possibilities of certain events and keep in mind that the poet uses certain devices — he likes the number "30" — to indicate significant measure.)
Grendel's mother has ruled the mere for "a hundred winters" (1498) — or a long time. She knows the territory. Only Beowulf's mail-shirt, made by the legendary blacksmith Weland, saves him from injury as she hauls him to her cave at the bottom of the mere. Neither her grip nor the "strange sea creatures / with sword-like tusks" can do him harm. The vaulted cavern, which has served as a hideaway for Grendel and his mother, is dry and lighted only by a glaring blaze (1517) that reminds the audience of the "ugly light" (727) that shines like fire from Grendel's eyes. It is, perhaps, a fire from Hell that lights the cave of Cain's descendants.
Like Excalibur, Hrunting is one of many special swords of legend, which Unferth inherited and gives to Beowulf as a token of the Geat warrior's superiority. We are told that Hrunting has never failed its owners until now, when it cannot pierce the hide of Grendel's mother. Then Beowulf notices "a victory-bright blade / made by the giants" (1557-58) waiting in the cave. Little more is said of this blades origins, except that the poet notes that no other mere man ever carried a sword of this length or weight into battle.
The "victory-bright blade" is just what Beowulf needs, and here the reader needs to consider, for just a moment, God's intervention. In this sequence, the Beowulf poet apparently has a Christian God control the outcome after Beowulf breaks free from the mother and stands on his own. Students may want to question whether this intervention is part of a Christian theme throughout the section (or the whole epic) or whether it is intrusive. Whether it adds to or detracts from the action is a matter of perspective. The best of critics have debated the point. At any rate, the sword is there, and in a life-or-death move, Beowulf takes one mighty swing at the mother and cuts through her spine, killing her.
Perhaps miraculously, the cave fills with brightness, "even as from heaven comes the shining light / of God's candle" (1571-72). The reader is again reminded of the motif of dark versus light, the darkness of the swamp and the light of Heorot, the dark of evil and the light of goodness in the epic. This light, whatever its source, also serves a practical purpose: Beowulf is able to explore the cave. Among various treasures, his most valuable find is the corpse of Grendel. With vengeance, Beowulf chops off the ogre's head. Eschewing all the other treasure, Beowulf leaves the cave and swims up through the mere taking only Grendel's head and the hilt of the giant sword.
On the surface of the marsh, things have changed. When blood began seeping up to the top of the mere, "a churning foam" (1593), Hrothgar and the Danes despaired of Beowulf's ever surviving and returned to Heorot. Only the Geats remain to keep a desperate vigil, wishing with no real hope that their leader would triumph. Beowulf emerges to a hero's welcome. The Geats help him out of his armor and joyfully march him back to Heorot. It takes four men to carry Grendel's head on a war-spear. The gruesome trophy makes quite an impression in the mead-hall.
kingdom of waters here, simply a reference to the mere and the ogres' hideaway.
the lord of those rings Beowulf, with a reference to the rings that form his mail-shirt.
battle-flame the sword, Hrunting.
burnished polished until glossy.
The bold Scylding the poet associates Beowulf with the Scyldings, perhaps out of respect for his loyal service, even though the champion is a Geat.
the shearer of life-threads the magical giant sword.
gray-bearded elders Hrothgar's senior advisors.
the ninth hour the "nones," the ninth hour after sunrise, 3 p.m. As Chickering points out (p. 338), this is "the same hour that Christ, abandoned by all but a faithful few, died on the cross (see Luke 23:44-46)."
protector of sailors Beowulf.