The Tunnel

The Tunnel is the second chapter of the fourth campaign, Blood Harvest. The survivors continue along the train tracks, passing through a train station and an underground train tunnel.

Encounter
In the Lower area of the factory that have to walk through there is an alarmed door that leads through the factory and onto some train tracks. When you open the door the alarm sounds and the Horde comes. Ammo is located next to the door as well as sometimes health.

Afterwards
After defeating the horde here, the survivors emerge outside and enters the tunnel. Many trains have crashed here, creating obstacles the survivors must traverse. After finally passing all the trains the safehouse appears at the end of the tunnel.