This order was commanded by the Wych Mistress, head of the Dark Eldar fleet. Her image projected large in holographic form on the Eldar bridge where the highest of seers watched over the ship's care and condition. The ancient Seer Iyand'imir stood proud despite his current circumstance.
Although they were caught surprised, the Craftworld fleet was not given to take well to threats. Quite simply, the Dark Eldar wanted souls. The Seer thought that any educated and ranking Dark Eldar would understand that this was a request which would go unfulfilled. Only respect for the nature of the plight of both races kept these occasional run-ins from turning violent.
"We have nothing to give you. Move along, Raider," the Seer commanded.
"You can conjure up some coordinates for us."
"We have nothing to give you, Raider. Move along." Repeated the Seer in an increasingly stern voice. There was no will to negotiate with the hedonistic under-dwellers of Eldar society.