The Sisters of the Orders Sabine accompany the Missionarius Galaxia on missions to rediscover new worlds. The Sisters specialise in infiltrating primitive societies and introducing elements of the Imperial Creed to the natives.
Sisters Sabine will sometimes set themselves up as prophets of the Emperor, preaching their creed in secret and fomenting revolt against leaders of an enemy world. When the Missionarius Galaxia arrives and announces its presence, the Sister Sabine announces their prophecies have come to fruition and lead more followers to the Imperial Creed. This can lead to natives launching sudden coups against their leaders. Their work however means that Sisters Sabine are isolated from the Imperium for a great many years, returning to their Convent perhaps only once in their lifetime.