While this entire Wiki contains spoilers, this particular article contains MAJOR SPOILERS for all books.
While appearing empty to casual inspection, under certain conditions the interior of the Shrike Temple changes. After the Time Tombs "opened," a series of stepped, concentric circular platforms appeared in the main room, upon which were laid hundreds of seemingly comatose humans. Each rested within a stone depression, and was linked to a metallic tentacle that penetrated their skin (usually using a neural interface). These tendrils connected the victim's consciousness to a virtual-reality simulation, in which they were impaled upon the Shrike's Tree of Pain. While their bodies were intact during the ordeal, in their mind each victim experienced unimaginable levels of pain.