In the quotation from Passage, Connie Willis states that literature is a way for authors from the past to communicate with readers of today. We can read their stories, books, and other texts to learn lessons about life. Willis refers to these lessons as messages from beyond the grave. Willis has a favorable viewpoint about the timelessness of literature.
Hrothgar is the man who is described in these lines.
He was a famous king, whose men kept dying because the monster Grendel killed them all, so he felt a dire need to seek help from the great hero Beowulf.
Length of the play best distinguishes a Greek tragedy from a Greek comedy.