You can start this quest after talking to Vehn Terev during the quest "Hunting the Archon", simply head to the southernmost part of Kadara - through the door marked as "The Docks" - and turn east to find a man named Grayson Wessler standing near some crates under some stairs. Give him a good talking-to and he’ll reveal that he was a little over-zealous in the exercise of his abusive duties as an Outcast, and as a result he may have exiled an innocent person. So, now some poor woman is trapped out in the dangerous badlands and he can’t afford to fix the problem properly, in case his boss finds out. Listen to his sob story (which SAM will annoyingly corroborate, if you express skepticism) then agree to help him out… or rather, help out the woman - Remi Tamayo - that he banished.
Take the lift down to the slums and make your way north to the checkpoint separating Kadara Port from the badlands, where you’ll find the Warden. Converse with this clerical Krogan and confirm that Remi Tamayo is indeed out in the badlands. Specifically, he’ll mention that she was last seen in the company of one Johan, and will suggest that any encounter with this group will not be a peaceful one.
Make your way to the badlands and from the first Forward Station follow the road east until you reach a fork, at which point turn south. Continue following the road south and southeast past a Point of Interest Collective camp and a Forward Station, after which the road will turn east and lead to various structures. The building you’re looking for - an elevated building suspended off the ground by a support pylon - is south of the road, just before the road turns north. Fight your way through Johan and his goons, which include an Anarchist, a Berserker (a Krogan that can absorb a great bit of damage), a Pariah and Sharpshooters, then go up the stairs and enter the structure.
Inside Johan’s base you’ll make a gruesome discovery regarding their source of sustenance. Fortunately Remi is still alive, simply activate a Cell Control Panel to free her, then chat with her to hear her story. A quick call to Grayson later and this quest will be over, netting you 29 AVP, +2% Kadara viability and 530 XP. Killing armed cannibals does have a way of making a place more livable.