These tweets relate to a gory section I remember, about the swimming down to fight and kill deep underwater:
"48. At mere’s bottom, grim & greedy, she gripped Beowulf, mail-coat-aided; benthic beasts struck as she hauled him to her fire-lit hall
49. With sword, the hero struck her head, but to no avail. Grabbing her hair, he fought hand-to-hand. She threw him down & drew a knife
50. Woven war-mail (& God) saved him. He spotted an old giant sword. Through her bone he cut. Light shone. He hacked off Grendel’s head
51. Above, Danes gave up at the ninth hour & left the Geats to stare at a blood-muddied mere. In the under-hall, the giant sword melted
52. Our hero swam up with head & sword-hilt, rejoicing in his victory. Loyal thanes thanked God; rode to Heorot to present the booty.
53. Beowulf spoke: “It wasn’t an easy fight, but divine intervention showed me a sword. Here, have the hilt. Now you’re free of fear.”