And one day a messenger came over the sea from another country close by, called Denmark, and the messenger said, 'Which of all you brave men will come over and help my master, King Hrothgar, who is in sore trouble ?' And the messenger told them how Hrothgar, for many years past, had been plagued by a monster--the hateful monster Grendel--half a man and half a beast, who lived at the bottom of a great bog near the king's palace.
Every night, he said, Grendel the monster came out of the bog with his horrible mother beside him--a wolf-like creature, fearful to look upon--and he and she would roam about the country, killing and slaying all whom they met.

Sometimes they would come stalking to the king's palace, where his brave men were sleeping round the fire in the big hall, and before anyone could withstand him Grendel would fall upon the king's warriors, kill them by tens and twenties, and carry off their dead bodies to his bog.

Many a brave man had tried to slay the monster, but none had been able so much as to wound him.
"When Beowulf and his friends had heard this story they thought a while, and then each said to the other, 'Let us go across the sea and rid King Hrothgar of this monster.' So they took ship and went across the sea to Hrothgar's country, and Hrothgar welcomed them royally, and made a great feast in their honour.

And after the feast Hrothgar said to Beowulf, 'Now, I give over to you the hall of my palace, that you may guard it against the monster.' So Beowulf and the brave men who had come over with him made a great fire in the hall, and they all lay down to sleep beside it.

You may imagine that they did not find it very easy to get to sleep, and some of them thought as they lay there that very likely they should never see their homes in Sweden again.