The seven pilgrims intend to travel to the Valley of the Time Tombs, where the Shrike, a metallic creature alleged to grant one wish to the members of a pilgrimage, dwells.

Powerful entities such as the Hegemony of Man and the Artificial Intelligence (AI) TechnoCore seek to influence the pilgrims' journey.

The novel also contains explicit references to classical literature and modern writings, including the scientific works of the Jesuit and paleontologist Pierre Teilhard de Chardin, the physicist Stephen Hawking, and some of the fiction of author Jack Vance.

Joseph Severn, the name assumed by a second John Keats AI persona, has dreams of the pilgrims on Hyperion.

He reports these dreams to Hegemony CEO Meina Gladstone, allowing the government to have real-time access to information about the pilgrims.

Before dying, he reveals that the Shrike Cult has colluded with the Templar Brotherhood, and claims that he was meant to pilot the Tree of Pain through space and time.

Gladstone is informed that the Ousters have counterattacked, attacking the WorldWeb itself in an unprecedented and unexpected move that appeared impossible.

Since FORCE fleets have been committed to the Hyperion system, the first wave of worlds threatened by the Ouster invasion seems destined to fall.

Intrigued by the collusion of the Templar Brotherhood with the Shrike Cult, Duré travels to God's Grove, which is soon to be attacked by the Ousters.

Severn and Gladstone's chief of staff, Leigh Hunt, attempts to farcast to Tau Ceti Center.

General Morpurgo leads a ship supposedly on its way to Hyperion with a Core deathwand technology designed to kill any human on the surface and all of the Ouster swarm.

The fatline, which utilizes the Void Which Binds for faster-than-light communication, is suddenly shut down by unknown forces.

The novel ends with the Consul returning to the former Web Worlds in his starship to discover what happened, with Severn's personality stored in his ship.