evenings.

"So liv'd on all happy the host of the kinsmen
In game and in glee, until one night began,
A fiend out of hell-pit, the framing of evil,
And Grendel forsooth the grim guest was hight,
The mighty mark-strider the holder of moorland,
The fen and the fastness."[10]

This monster, Grendel, came from the moors and devoured thirty of the
thanes. For twelve winters he visited Heorot and killed some of the
guests whenever he heard the sound of festivity in the hall, until at
length the young hero Beowulf, who lived a day's sail from Hrothgar,
determined to rescue Heorot from this curse. The youth selected
fourteen warriors and on a "foamy-necked floater, most like to a
bird," he sailed to Hrothgar.

Beowulf stated his mission, and he and his companions determined to
remain in Heorot all night. Grendel heard them and came.

"...he quickly laid hold of
A soldier asleep, suddenly tore him,
Bit his bone-prison, the blood drank in currents,
Swallowed in mouthfuls."[11]

Bare-handed, Beowulf grappled with the monster, and they wrestled up
and down the hall, which was shaken to its foundations. This terrible
contest ended when Beowulf tore away the arm and shoulder of Grendel,
who escaped to the marshes to die.