Pattern Juggler

This is a list of fictional alien and modified human races in the fictional Revelation Space universe created by Alastair Reynolds.

Denizens are a heavily engineered sentient species created on Europa by the Europan Demarchy. They possess varying levels of intelligence, ranging from animalistic to baseline human capabilities, but are invariably of great physical strength and well adapted to life in the Europan ocean. Their most unusual adaptation is their ability to utilize hydrogen sulfide instead of oxygen in a modified human body (Europa's oceans may contain a high sulfur content). The Denizens were originally created for slave labour, but the project was abandoned after infighting amongst Demarchy researchers. A few Denizens, however, survived and retreated into the volcanic vents of Europa. Later on, Cholok, a Europan defector, tricked Agent Marius Vargovic of Gilgamesh Isis (an anti-Demarchy faction that controlled Ganymede and Callisto), into giving the Denizens a virus containing genes that would let them survive in the oceans outside the vents (to better control them, the Denizens were previously unable to survive in the cold oceans of Europa without assistance), at the cost of his own life. The Denizens later mounted a rebellion destroying the first Europan Demarchy.

Gillies are a faction of humans that have been bioengineered to live underwater. Due to the different pressure properties of liquids and gases, this enables them to crew short-range, high-g intra-system ships. Most gillies are just normal people or labourers that work in submarine conditions, with barely more than gills on their chests distinguishing them from baseline humanity. Some gillies are mentioned as being so adapted to a submarine environment they cannot breathe or function in air anymore and have to be transported in huge robotic tanks. Their origins were revealed in the story "A Spy in Europa", featured in Galactic North.

The Grubs are a spacefaring civilization. They are named "grubs" by humans due to their general appearance. When they first developed starships, they were nearly exterminated by the Inhibitors. Some survived by hiding in the interstellar void, adapting themselves to near absolute zero conditions to avoid detection. During that time, some of them encountered the Nestbuilders and the Jumper Clowns, and received technology from them, including FTL communication (but not travel).

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