Camp Agrophylake (Location)
An imperial camp in Ineb-Hedjet Nome.
The treasure in the central tent, the captain will either be there or guarding the prisoner cage.
The guards here have an odd tendency to face the wrong way. You can pick off the whole western edge with sneak attacks (Note that the spiked barricades here don't actually harm or impede Bayek).
Continue to stealth kill west-to-east across the camp. If you have the chain assassination ability, you can put it to use here as well.
Kill the captain that way, or just sneak around the tent to get a drop on him. Either way, once he's dead you can loot the giant red chest in his tent for completion.
You can also free those caged prisoners for XP.