The summary provides details about three key sections of the document:
1) It describes Beowulf's journey to Denmark to help King Hrothgar defeat the monster Grendel. It outlines Beowulf's introduction to the king and his defense against accusations from Unferth.
2) It summarizes the battle between Beowulf and Grendel, where Beowulf is able to rip Grendel's arm off.
3) It discusses the aftermath of the battle, including Hrothgar praising Beowulf and giving him gifts. It also notes the ominous foreshadowing of a tragic story sung by the minstrel.