"Locate the warden" is the first mission objective in Sequence 2 / Memory 05: Claiming What's Due
Walkthrough[edit]
Use your eagle vision to located the Warden.
Once you spot him, a red key will appear on his head (see screenshot)
Be sure to stay in hiding places and Stalking Zones so that you are not detected
When you enter stalking zones (such as bushes) there will be a brief animation showing that you are hidden