Investigate an infected area is an objective in the Story Mission, Spore Chores in Borderlands 2: Commander Lilith and the Fight For Sanctuary
- Just outside the Backburner, start heading to the South, through the remains of the defenses here.
- Use the nearby Catch a Ride station to summon in the vehicle of your choice.
- Head to the Southwest, be ready for at least 1 Bandit Technical in the area after the Vault Hunter.
- From there, find the Miasma Sink