Darkness Looms – Complete the final mission of the Missing Persons Investigation
There are six bodies to find. After you unlocking ctOS Towers they location are shown on the map. To see the last two in Pawnee (yellow) on your map, you need to reach Act 3.
Unlocks: After you find the 5/6 Missing Person you unlock the Wildfire (4 Star Full-Auto Assault Rifle, with 30 Bullets)