As you walk through the markets, you find parts and upgrades. In the previous clip, you found Kenn the Quarian, who's stuck where he is trying to sell parts. An Elcor, Harrot, is forcing him to keep his prices high so that he can't sell anything. To really help him, you give him 1K credits to get him back on his pilgrimage.
At the entrance to the Quarantine zone, a guard initially keeps you out. When you offer to help clean the problem with the Blue Suns and the Vorcha, he agrees to let you through.