author: Satyarth Mishra Sharma

Two images are given: a map with a starting point and direction indicated, and a very sexy looking screenshot. The screenshot consists of a number of tiled windows, one of which is an image of autumn leaves. Another window has a manpage for a tiling window manager, whose layout is represented by a binary tree. The title and the manpage hint to binary trees being important in the solution.

The map is of central Cambridge. Some consideration will lead to the realization that at each fork in the road, there's two possibilites... a gasp binary tree! So how do we traverse this tree? Well, the only other clue we have is the screenshot, so the information must be encoded there. Connecting the name of the puzzle and the image of the leaves, we see what the positioning of the leaves within the layout (a binary tree) holds the key. To get to the leaves, you have to partition left, up, left, down, right. Another window on the screenshot tells you 'left = up, down = right'. Thus if you start at the indicated point on the map and follow the directions (left, left, left, right, right) at intersections, you arrive at a dead end in an alley. Looking around you find a piece of paper with the CUCaTS logo on it stuck to a trash can, with the text "Grey face (no space)". The final answer is "Greyface".