This is earned by following the main story, where you’ll cleanse the following:
- Central Executive; this has to be cleansed in order to continue with the story, during mission 1 after defeating ‘Ranger Second Class Polaski’.
- Dead Letters; found during mission 2 next to brown double doors marked ‘Communications Department’.
- Mail Room (just outside); found during mission 2. When facing the doors to the ‘Mail Room’, this is to the left hand side.
- Maintenance; found at the beginning of mission 3. After leaving the elevator, follow the signs for ‘NSC Control Room’ and through a Level 2 authorised room. Follow the corridor past the control room and up a set of stairs, the control point is at the top.
- NSC Power Plant; during mission 3. This can be found just outside the ‘NSC Security’ room Arish is found inside, up a ramp on the left.