22. Shadows Walk

It will be pitch black inside so you'll only have to rely on your pistol for illumination. There are only some parts of the tunnels that are dark so use the pistol to illuminate the area and engage the enemies on lighted areas using your primary/secondary weapons.

Continue inside then continue following the power cables to reach the exit. Be careful around the corners as there are enemies waiting to ambush you. Kill the brute in the last part of the tunnel to reach the exit and complete the section.