Infernex, Inc.
Owned by the Hellknights and orbiting the Pact Worlds’ sun, this shipyard builds the massive black citadels and austere starships used to carry out official Hellknight functions. These vessels make only limited concessions to human needs but include plenty of space for imprisonment, interrogation, and punishment. The Hellknights reassure governments worried about the presence of these moving citadels that only those who break the law must fear Hellknight justice. More than one troublesome prisoner has disappeared forever within an Infernex, Inc. starship, where minions of Hell such as imps serve alongside Hellknights as crew, performing basic maintenance and even enchanting the ship’s components and weapons.
Source
Starship Operations Manual pg. 67