Orlights

Orlights are a fictional species appearing in the science fiction novel "The Book of the New Sun" by Gene Wolfe. They are described as a type of luminous, gelatinous creature that inhabits the subterranean regions of Urth. Orlights are characterized by their soft, pulsing glow, which can range in color from pale blue to vibrant green. They are not sentient in a human sense and seem to exist primarily as a source of light and a minor environmental hazard.

The precise nature and origin of Orlights are not fully explained in the novel. They are often encountered by the protagonist, Severian, during his journeys through the dark and forgotten parts of the world. Their bioluminescence is a key feature, often serving as the only illumination in the deep underground. Some passages suggest they may feed on decaying organic matter or minerals, though this is speculative.

Despite their seemingly simple nature, Orlights contribute to the dense and often mysterious atmosphere of "The Book of the New Sun." Their presence underscores the alien and decaying nature of Urth in the far future. They are a recurring element that adds to the novel's unique world-building, serving as a reminder of the strange life forms that persist in the planet's deepest recesses. While not central to the plot, their visual description and passive existence are memorable aspects of the narrative.