This poem has no setting (environmental context), yet it establishes an atmosphere of uncertainty and, possibly, of terror. How does Keats create this atmosphere? The poet is dying and knows he is...

This poem has no setting (environmental context), yet it establishes an atmosphere of uncertainty and, possibly, of terror. How does Keats create this atmosphere?

The poet is dying and knows he is dying—why does he then labor so over the rhyme and meter of this poem? What does the poem do for the dying narrator?