On July 24, 1989, two hikers from Tokyo had gone missing while climbing to the summit of Asahi-dake, the highest point of Hokkaido. As the sun was setting, a helicopter search crew made a startling discovery: a crude but massive SOS sign, constructed of fallen trees. The search parties converged on the vicinity of the sign, and found the two men in a cave about two or three kilometers north of the sign, frightened and dehydrated, but otherwise unharmed. The rescuers commended the hikers for building the SOS sign, as they wouldn’t have been able to find the hikers without it. However, the hikers were confused - they had no idea the sign existed, and were too exhausted to build such a sign as it was. Realizing that there were probably other missing people on the mountain, the Japanese police sent more people to search the site of the distress sign. Upon further examination, the SOS sign was not built of random deadfall, but instead cleanly chopped logs.…