The rat leads you out to the street. Looking down, there are half a dozen different types of manholes on the street. Which one leads to the sewers? Clicking on the wrong one will give a quick sound/image blurb of what it is. Our motivation here is to show how there are multiple utility systems that exist, follow the same paths, and require access by people to fix them.
While trying to figure out how to get into the sewers, the first in a sequence of Dr. rat segments occurs. Dr. rat is an alter ego of the narrator character who we use to get across a set of technical sidebars that doesnıt flow quite as naturally into an exploration framework.
Dr. rat pulls down a projector screen out of the top of the monitor. It has an image of a cross-section of ground, based on an image in David Macauleyıs Underground. It shows the relative positions of the different pipes. Find the right manhole, and head into the sewers...