First understand where you are. Then see where you can go.
PATH is the layer that begins after Intelligence has answered the question. It turns a supported explanation into a map of possible routes — without choosing the route for you.
Underground, the problem is not moving. It is knowing where you are.
The idea comes from Toronto. Beneath downtown, PATH connects buildings, transit and destinations through an extensive pedestrian network. Once underground, the usual references of the surface disappear. You can keep walking and still not know whether you are getting closer to where you need to be.
You do not need more tunnels. You need orientation.
That is the idea HOWEDOING borrows. An investigation can give you a great deal of information. Intelligence establishes what that information allows us to know: YOU ARE HERE. PATH begins there and makes visible the routes the evidence opens from that point.
The colors orient. The evidence defines the routes.
The four directions are not four fixed services or four automatic recommendations. They are a visual orientation language. Each investigation determines which routes actually exist.
Intelligence tells you where you are. PATH shows the routes the evidence opens. You decide which one to take.
If a route creates a new question, it returns to the Method. If the right move is to observe, WATCH follows what happens next.