Beowulf gazed down into the deep waters, saw that they also were darkly dyed with the monster’s blood, and, after taking leave of Hrothgar, bade his men await his return for two whole days and nights ere they definitely gave him up for lost.  He then plunged bravely into the bloody waters, swam about seeking for the monster’s retreat, and dived deep.  At last, descrying a phosphorescent gleam in the depths, he quickly made his way thither, shrewdly conjecturing that it must be Grendel’s hiding place.  But on his way thither he was repeatedly obliged to have recourse to his sword to defend himself against the clutches of countless hideous sea monsters which came rushing toward him on all sides.

“While thro’ crystal gulfs were gleaming
Ocean depths, with wonders teeming;
Shapes of terror, huge, unsightly,
Loom’d thro’ vaulted roof translucent.” 

                                                  J.C.  JONES, Valhalla.

A strong current seized Beowulf, and swept him irresistibly along into the slimy retreat of Grendel’s mother.  She clutched him fast, wrestled with him, deprived him of his sword, flung him down, and finally tried to pierce his armor with her trenchant knife.  Fortunately, however, the hero’s armor was weapon-proof, and his muscles were so strong that before she could do him any harm he had freed himself from her grasp.  Seizing a large sword hanging upon a projection of rock near by, he dealt her a mighty blow, severing her head from the trunk at a single stroke.  The blood pouring out of the cave mingled with the waters without, and turned them to such a lurid hue that Hrothgar and his men sorrowfully departed, leaving the Geates alone to watch for the return of the hero, whom they feared they would never see again.

Beowulf, in the mean while, had rushed to the rear of the cave, where, finding Grendel in the last throes, he cut off his head also.  He seized this ghastly trophy and rapidly made his way up through the tainted waters, which the fiery blood of the two monsters had so overheated that his sword melted in its scabbard and naught but the hilt remained.

                          “That stout sword of proof,
    Its warrior task fulfill’d, dropp’d to the ground
    (So work’d the venom of the felon’s blood)
    A molten mass.”
                                Beowulf (Conybeare’s tr.).

The Geates were about to depart in sorrow, notwithstanding the orders they had received, when they suddenly beheld their beloved chief safe and sound, and bearing the evidences of his success.  Then their cries of joy echoed and reechoed from the neighboring hills, and Beowulf was escorted back to Heorot, where he was almost overwhelmed with gifts by the grateful Danes.  A few days later Beowulf and his companions returned home, where the story of their adventures, and an exhibition of all the treasures they had won, formed the principal topics of conversation.