Sequel to Hyperion (not seen), a vastly involved alien-contact/galactic war drama. In the far future, Earth has been destroyed, though humans have established a galactic empire, the Hegemony, run by CEO Gladstone; instantaneous interstellar travel is available via ""farcaster""; the Core, meanwhile, composed of linked Artificial Intelligences, studies human affairs through the use of ""cybrids"" like the genetically-human Joseph Severn, who can access much of the Core databanks directly and bears the personality imprint of the poet Keats. Gladstone, curious about artist Severn, invites him to high-level planning sessions--the Hegemony, you see, is preparing to defend planet Hyperion against invaders, the mysterious Ousters whose Swarm is claiming Hyperion. However, Hyperion is the site of the enigmatic Time Tombs, huge alien artifacts shaped like weird buildings. Seven human pilgrims are now wandering Hyperion, exploring the Tombs and awaiting the painful attentions of the Shrike, an alien creature that, among other things, will grant the wishes of one of the seven but slaughter the other six. Severn follows the pilgrims' adventures by dream-link with one of them, another Keats imprint. Readers who glory in sheer complication will find much to admire here. Others, who haven't read Hyperion and therefore don't know what's going on or why any of the above should matter, will not find the narrative enlightening.