During the seige of Gravalax, [[Tau]] forces, who were stationed there had grown weary of the human presence and had tried to keep order in the human parts of the city as well. Fearing the Tau liberators, the Ordos Xenos sent Inquisitor Vail to investigate. She disguised herself as a singer (also wooing Cain over)) and infiltrated the Imperial Governor's palace. After escaping the tunnels of the planet during a more in depth investigation, she enlisted Cain to dig further into the planet's tunnels ( and found out that Cain's aid [[Jurgen]] was a [[blank]] ). The troop found a gene-stealer cult, and eliminated it's leader.