The Good Roman (Side Quest)
A side quest in the Green Mountains
Pass by the objective marker to witness a confrontation between Romans.
Vitruvius will task you to find his lost dioptra. The man you need to question, Dedi, is atop the aqueduct- Senu can find him.
Initially he'll run from you- just keep up and he'll eventually stop to talk.
His testimony sends you to a big scary cave above the camp.
This is the Necropolis Hideout (as opposed the Necropolis Bandit Hideout south of Lake Mareotis, though this one is also filled with bandits)
Enter the cave, and climb up the water fall.
You'll find yourself a the bottom of a great well. Climb out of this too, aiming for the wooden landing above.
There may be bandits up top, though not on guard. Safest to take them out anyway.
Head east, until the tunnel opens up.
One of the Hideout captains is stationed atop the platform here. Decommission him.
There's one other legendary-looking warrior here- deal with him as you like.
Loot the room, then head through a doorway south.
The first dioptra piece will be on a table here, next to some scrolls.
Smash the pot to the right of this table to reveal a secret passage.
Shimmy through to loot the location treasure here- a carbon crystal.
Exit and head west to the hanging tree, disposing of one guard along the way.
Keep heading west, toward the civilians. This cave houses the prison, and there's a lot going on here.
But first, take out the two hostiles, one likely on ground level, the other up on the balcony.
Go up to the balcony. On the desk here is a letter which triggers the Taking Liberty side quest.
Loot the balcony guard's body for the second piece of the dioptra.
Getting the last piece can be confusing, because the marker here is indicating the search area, not the piece itself,which just at the southwest end of this same platform.
While you're here, you can also free the prisoners, but they tend to run uphill, right into the bandit camp, so you may want to clear that first.
The camp itself is heavily guarded, but not overly rewarding. If you just want to complete the mission, return to Vitruvius, otherwise head upslope to the camp itself.
The last treasure is in the middle of the ruin, in a red box. You can kill your way there, or cause a distraction (freeing the animals, or the prisoners, or setting something on fire are all proven go-to's).
The commander tends to hang out in front of an alternate entrance to the cave, at the south side of the ruins. There's a line of bushes in the yard above perfectly designed to aid a stealthy approach.
Dropkill from the ledge to seal the deal.
His death completes the location.
Return to Vitruvius in camp and speak with him to complete the quest.