You are a former facility worker, investigating the inside of a building you used to work at. You've already encountered some decaying infected along the way, but you fended them off with concrete bricks scattered around the place. Eventually, you find and go inside a large tunnel for fast travel, and things were looking normal about it so far, until you heard loud, speeding footsteps ahead. You stop in your tracks as a flash of blue light dashes right in front of you, catching a glimpse of an electrified creature before it disappears on the other side, echoing a distorted laugh throughout the tunnels. You need to get to the other side of the tunnels, so you have no other choice but to continue forward and face the risk forebodingly.