Ilium
by Dan Simmons
This 700-page, Hugo-nominated adventure of the distant future is packed with incident and invention. We have old-style humans on earth, we have post-humans in the earth's rings, we have robotic cyborg intelligences called moravecs mining Jupiter and discussing Proust and Shakespeare among themselves. On Mars, we have little green men. Somewhere, we have a vast reenactment of The Iliad unfolding on the plain of Ilium, with real blood and real gods and with everything witnessed by a team of reincarnated classics professors.
At the end, the characters agree that they're eager to discover what happens next -- presumably, in the second volume.