A team of archaeologists in Mexico's Yucatan peninsula accidentally triggers a viral epidemic. Medical researcher Robert Asher uncovers a mysterious glyph chiseled into a stela in Uxamal in the ninth century, hinting that an identical virus may have decimated the ancient Maya. This leads ti the possibility of a cure that could be the key to saving millions of lives. Asher and Maya scholar Teresa Welles seeks the answer in Uxamal and in the caves below Tulum. The stakes are high and escalate quickly as the virus spreads, but an unexpected armed force defends the caves . . .