The Triumvirate of the Primarch was the name given by observers to the odd tripartite alliance between a Primarch, a Grey Knight and a Fallen Angel during the Terran Crusade ... and perhaps beyond. A strange fate binds Roboute Guilliman of the Ultramarines, Grand Master Aldrik Voldus of the 3rd Brotherhood of the Grey Knights and the enigmatic Fallen Angel Cypher together.