The aging scientist had illustrated this uncommon technique using the recovered portion of a wall with text. It had been excavated years before, and extensively studied since. The fragment of wall was kept in the basement at the archeological school where Bryce was studying.
Using a dim light Bryce's professor illustrated how hidden messages were only visible if the lighting was just right. To be read, the text would need to be seen at the correct time and date. After years of study it was believed to be most visible during the Vernal or Autumnal Equinox. Furthermore, sunlight would not work. The sun was too bright. The secret messages could only be read under a full moon. Additionally, the moon must be directly overhead without clouds. If a message was hidden there Bryce would need to act quickly. Whatever might be there would only be visible for the few minutes the moon cast shadows perfectly downward.
Bryce told the men he should return to the university. He wanted to discuss this discovery with his professor. The men understood nothing more could be done and agreed to bring Bryce back whenever he returned. The large stone was pushd back into place resealing the opening. Satisfied it was again well hidden, Bryce and the men hiked back down the mountain to the village. The next morning Bryce returned to Caja Marka. Checking the lunar calendar it was now obvious he would need to return to the village in two weeks. If he planned it right he could arrive ahead of the Vernal Equinox and the next full moon.
Bryce returned to the village two weeks later. His first day was spent helping a friend, one of the men who had taken him to the site. When they stopped for lunch Bryce explained what might have been hidden on the panel. Later that evening Bryce met with the other men for a few bottles of beer. They listened intently as Bryce explained his suspecisions. They were genuinly excited by this news and wanted to return the following day to find out if his theory might be correct. The moon would be full that night and they meant to stay at the ancient city all night if necessary.
The next morning Bryce met everyone before dawn for a typical Andean breakfast. The first slivers of golden sunlight streaked across the deep blue sky as they started the long vertical hike back into the mountains.
Part 4 tomorrow...