This section of the guide contains information about the Terra Infirma side mission in Outriders. Here you will find a detailed walkthrough of the mission. Terra Infirma is the third side mission in Outriders. You will have to find Lieutenant McCain.
The mission consists of several areas where enemies flow in all the time. If you look around the locations well, you should also find a couple of chests. Keep moving forward all the time and take down enemies.
In the place from the image above, it might prove more difficult due to snipers guarding the passage. A little further away there's an elite enemy. Clear the ruins and then keep going forward. The mission will end when you report the situation to Shira.