Walking--or rather, climbing--was not easy. The Maple branches varying in size and sturdiness, sometimes swaying alarmingly beneath me. That, and every time I looked down I thought I might vomit.

At first I tried to follow what I assumed was the general direction of the branches, reasoning that they would all eventually reach an end too thin to stand on or would return to the trunk. Instead, I found myself walking in circles, returning to the same space again and again, no matter how ...