"Loot the warehouse" is a mission objective in Sequence 3 / Memory 05: Sugarcane and its Yields
Walkthrough[edit]
Use Stalking Zones to assassinate any guards near the warehouse, or any patrols in the area
If you are spotted, you will not be able to open the warehouse until you become anonymous again - in that case, either flee and come back to try again, or kill all the guards near the area
This ends the memory. There should be a Rowboat nearby that can take you back to the Jackdaw quickly