Saturn

Saturn is a restricted Inquisition fortress whose rings and moons sit off-limits to ordinary Imperial traffic. The Saturnyne Ordo once ruled here as a sibling empire until the Emperor absorbed it, and Malcador later locked the region as a quarantine zone. Night Lords dumped corpse-ships into its habitats during the Solar War; by M32 the Ordo Malleus owned the sky. Titan's Grey Knights citadel is a different Sol pin, already covered in wave 1.