Sark Malark instructs you on how best to obtain your Imperial disguises for the infiltration attempt.
This quest is available if you have completed both of the following quests:
Starting the Quest
Talk to Sark Malark in Revenant's Toll in Mor Dhona to begin the quest.
Obtain Uniforms and Helms
Go southwest to go through the southwest gate of Revenant's Toll, and go to where the orange arrow is pointing in the minimap. There will be quest icons in the minimap displaying the locations of Imperial enemies. Whenever you defeat them, there is a chance of receiving a uniform or helm. Since it is random, keep defeating the enemies until the quest objectives are marked as complete. Be sure to only attack the ones with the quest icons over their heads, to ensure that you have a chance of getting the quest items.
Present the Imperial Equipment to Sark Malark
Go northeast back to Revenant's Toll and talk to Sark Malark to hand over the uniforms and helms.
Deliver the Imperial Equipment to Eginolf
Go northwest and then north through the archway. Go through the first door on the right and talk to Eginolf. Hand over the uniforms and helms. There will be a cutscene.
Present the Repaired Equipment to Sark Malark
Go through the door and go south. Talk to Sark Malark to hand over the uniform and helms.
Next Main Scenario Quest
After you complete the quest, talk to Glaumunt to accept the next quest: Fool Me Twice.