The Sleepers Below is the name given by the Ilee of the planet Apostae to a cylindrical chamber miles long and hundreds of feet in diameter, criss-crossed by metal walkways. Thousands of glass-smooth eggs lie beneath the walkway, within each of which floats a single creature in stasis. The eggs' sizes range from fly-sized to colossal. Thousands of tiny crab-like creatures scuttle and probe over them, sometimes injecting an unknown substance or surrounding them in an electrical nimbus. Visitors from other planets might spot others of their kind within the eggs, albeit dressed in weird clothing and markings.
Some Ilee believe that the creatures within the eggs are their cousins, whom they have to protect until the mythical Day of Awakening. Others seek to actively awaken them (as the Day of Awakening will only come when the Ilee are strong enough), but are thwarted in their efforts by the tiny machines. Yet others think that the sleepers are the true power source of Apostae, and the Ilee are just a dream that will end once the sleepers awake. Grandfather Stone remembers that the original purpose of the Sleepers Below was related to zoology, but he cannot recall whether its goal was to take samples or introduce fully formed creatures to habitable planets.