Plesionhudir Hideout (Location)
A bandit hideout on Ineb-Hedjet Nome, You'll scour this one clean with an army of allies in the Lies of the Scarab Main Quest, so no need to clear it on your own first.
You can kill the captain in the mad melee, but the chest is in the central tunnels, on the lower level, in a red box (the same level as the captured priest, but one room west)
Take the loot to complete the location.