A secret Havenite planetary prison was located on Hades, often referred to as "Hell", a planet in the Cerberus System. The location of Hades and the Cerberus System itself was a state secret, known only to InSec and its successor, the Office of State Security. Because the prison was an unacknowledged rumor, it served as a terror threat to any possible opposition. And as it did not officially exist, State Security felt itself unconstrained by the Deneb Accords in its management of the planet.