Which line from the epic poem best explains why Beowulf undertook his quest? The hero arose, surrounded closely by his powerful thanes. The hero arose, surrounded closely by his powerful thanes. Nobody tried to keep him from going, no elder denied him. Nobody tried to keep him from going, no elder denied him. If Grendel wins, it will be a gruesome day. If Grendel wins, it will be a gruesome day. In his day, he was the mightiest man on earth.