Shadows of Apollo (Side Quest)
A sidequest available in the Roman barracks on the north side of Balagrae.
Scans show a well-populated but segmented fort- with the captain lingering in his office in the center building or the campfire east. The treasure and quest marker float below on some subterranean level.
Come in from the rocky wall on the north. This will give you an easy shot at clearing the battlements here.
You can then use the walls, catwalk, or rope here to get a vantage on the captain.
You'll have to carry someone out of here soon, so consider clearing away some soldiers from the gate.
Getting to the treasure room can be a little confusing, because the underground entrance isn't on the lowest floor of the complex. Instead, enter the door nearest the north east privy.
Take the narrow stairs down.
Now you can loot the treasure from the red chest in the corner.
This completes the location.
Now you can start the quest proper by freeing the prisoner here.
At least you don't have to carry him. Instead, escort him out the front gate, dealing with any soldiers you haven't already iced.
Once you're a goodly distance from the fort, speak with him again to complete the mission.