Detective Flanders and the Zodiac Killer

9. The Map

You know that on a map or in a spreadsheet, letter and number coordinates run along the top and left edges. Or looking at a chart, the x-axis runs from left-to-right along the bottom and the y-axis runs from bottom-to-top along the left. In all of these cases, one single coordinate from each axis is used to define a particular place on the map, spreadsheet, or chart.

This map also has axes with coordinates. But it uses a different system. Take a close look at the different five areas on the map (the mountains, the flowers, the dark mound, the pond, and the long stream). Each area is hiding a letter. Those five letters spell out the symbol that this map uses for its mapping system.

Each combination of two trees side-by-side represents a two-digit number. And ten total trees means each one is assigned a digit from 0-9. Ready to start assigning?

Think about how we count two-digit numbers:… 18, 19, 20, 21 …

As soon as the tens digit changes — as in going from 19 to 20 — the last digit immediately becomes 0, right? Same thing going from 29 to 30, or from 39 to 40, etc. The moment the left digit changes, the right one must be 0.

Same with our trees. After all, they all represent two-digit numbers!

Keep in mind these two Axis Rules:

The x-axis counts up from bottom left to bottom right.
The y-axis counts up from bottom left to top left.

Look at the five tree pairs on the x-axis (running along the bottom of the map). Going from the first pair to the second pair, the left-hand tree changes! So the right-hand tree of the second pair (the three-layer Christmas-y thing) has to be 0.

And if we follow the first Axis Rule, the right-hand trees in all five squares on the x-axis become 9-0-1-2-3. Okay, we’ve already assigned half the numbers!

Now go to the right-hand trees along the y-axis. You’ve already met 9, 0, and 1, recognize them? And according to the second Axis Rule, the two trees before those should be the two numbers before 9 (in order).

Cool, there are only three numbers remaining to be assigned: 5, 6, 7. And they go to the three left-hand trees still waiting for assignments. Keeping the two Axis Rules in mind, you should be able to figure them faster than a toupee in a hurricane.