Incoming Threat
This quest is part of the main game, but is made to introduce the DLC 'The Hidden Ones.' It launches with a unique orange colored marker, closing on your position. Despite the ominous name, this marker is just a messenger, giving you the letter that kick starts the mission.
Your first stop is Sarangina Camp, in Libue.
Even if you've cleared out this camp before, you'll see a new officer in charge of the operation.
As before, the gap in the the northeast wall makes an ideal stealth entry point. Though you do have to kill everyone here, so if you're a level 40+++ type just returning for the DLC, you may not want to bother with sneaking.
If you take the silent path, dispose of the guards as normal, then find the commander and his cronies sitting around in the haypile. Amongst some giant oil jugs.
Blow up the jugs, then pick a remarkably intact letter from the officer's charred remains.
This gives you your next round of objectives- three carts to destroy, and an enemy to assassinate. The carts are fairly simply- just smash the giant jars to render them worthless. The easiest cart is the one to the north, in Kanapos Nome.
The half-handful of guards here barely constitute a defense. Snipe them and smash all four jars, including the once on the ground just behind the cart
The bribe in the Limestone Quarry is better secured. If you don't want to fight everybody, come in from the west, and drop down the wooden platforms of the quarry wall.
Drop kill the guard, and find the cart just inside the door.
Smash the jars. If you haven't raised the alarm yet, you can quick travel out, and make for the last two objectives in the Pissa Oros Citadel.
Approach from the nearest gate- in the northeast of the citadel. The guards here have a convenient habit of facing the wrong way.
Assassinate them, then climb up the parapets. Clear out the two or three nearby guards- your goal is to secure the ammo caches here and in the tower.
With these under your command, headshot everyone in the square below, starting with Jibade. You'll need to confirm the kill to complete the mission, and you don't want him wandering off.
When everyone's dead, descend to ground level, and destroy the bribe cart. Note that this one only has three jars, rather than the usual four.
Finally, confirm the kill to end this part of the mission, and get a quest marker back in Alexandria.
Follow the marker, but don't rush straight in – the target villa is swarming with guards.
Dispatch them, or at least the ones on the ground floor, and inspect Otis' body to begin an investigation.
The trail of clue leads upstairs, but the clincher is the large green-striped jar by the bloodied bed.
Smash it and read the secret notes within to compete the mission.