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Thyst is one of Bretheda's notorious death moons. Thyst is radioactive and deadly to normal humanoid life, with cancerous rivers capable of melting unshielded flesh from bone.
Thyst is home to a race of strange, light-absorbing humanoids who are rarely seen, as well as unique animals adapted to the radiation. The barathus maintain prison camps on Thyst, where those convicted of violent crimes or violation of the regulations against the reverse-engineering of Confluence Agents' instant communication are held. These criminals, as well as the most downtrodden, harvest minerals on the moon's surface or study its unique fauna. Recently, a group of Eoxian immigrants, capable of withstanding the radiation, have settled on Thyst, established the settlement of Pharain, and are currently petitioning the Pact Council for the status of member or independent protectorate in the Pact Worlds. As the bone sages are demanding their repatriation, the Pact Council has begun an investigation.