"These Fallen sure know how to keep us on our toes."
Shaw tells you that Eramis has been trying to recruit her old comrades from the former House of Devils for a while; for her to arrive in person now must mean she's growing desperate.
Word is, she brought along a trusted sergeant, Bakris, the Adamantine, and empowered her with Stasis as a demonstration of the forces at her disposal. Shaw suspects the sergeant has remained in the Cosmodrome in order to ensure the Devils follow through on their pledge to relocate to Europa.
Locate Bakris, the Adamantine and scatter the Devils before they leave for Europa. Defeat Fallen in the Cosmodrome, The Divide.