The Anathema Psykana, also known as the Sisters of Silence, are an anti-psychic militant order in Warhammer 40k.
They are the militant arm of the Adeptus Astra Telepathica and are internally referred to as the organization's Departmento Investigates. However, their affiliation with this body is largely symbolic, and in truth they are an autonomous military force answering directly to the Emperor and the Lord Commander of the Imperium.
Together with the Adeptus Custodes they represented the Talons of the Emperor, with the Sisters as the left hand of the Emperor. Fragmenting after the Horus Heresy, they were brought back under Imperial control by Roboute Guilliman in M42. Their ranks consist entirely of blanks.
