Dominique gazes at the sheer, vertical walls of the sinkhole, which plunge straight down to the surface of its inky, algae-infested waters. The lunar light from the three-quarter moon highlights layers of geological grooves sculpted along the interior of the chalky white limestone pit. She looks up, focusing on an enclosed stone structure suspended over the southern edge of the cenote. One thousand years ago, the Maya, desperate after the sudden departure of their god-king, Kukulcan, had turned to human sacrifice in an effort to forestall the end of humanity. Virgin women had been locked in this primordial steam bath for purification, then led out to its rooftop platform by ceremonial priests. Stripping the young maidens naked, they would stretch them out upon the stone structure, then use their obsidian blades to cut out their hearts or slice their throats. The virgins’ bodies, laden with jewelry, would then be ceremoniously tossed into the sacred well.

The thought causes Dominique to shudder. She circles the pit and hustles down the Sacbe, a wide, elevated footpath of soil and stone which cuts through the dense jungle until it reaches the northern border of the ancient city.

Fifteen minutes and a half dozen stumbles later, Dominique emerges from the path. Standing before her is the northern face of the Kukulcan pyramid, its jagged, dark outline rising nine stories against the star-drenched sky. She approaches the base, which is guarded on either side by the sculpted heads of two enormous serpents.

Dominique looks around. The ancient city is dark and deserted. A cold shiver runs down her spine. She begins climbing.

Midway up, she finds herself gasping for breath. The steps of the Kukulcan are quite narrow, the rise steep, and there is nothing to hold on to. She turns and looks down. A fall from this height would be her last.

“Mick?” Her voice seems to echo across the valley. She waits for a response, then, hearing nothing, continues climbing.

It takes her another five minutes to reach the summit, a flat platform supporting a square two story stone temple. Feeling dizzy, she leans against the northern wall of the structure to catch her breath, her quadriceps muscles still burning from the climb.

The view is spectacular, with no safety rails. The moonlight reveals shadowed details of every structure in the northern section of the city. Along the outskirts, the jungle canopy spreads out across the horizon like the dark borders of a canvas.

The walkway around the structure is only five feet wide. Staying clear of the precarious ledge, she wipes the sweat from her face and stands before the yawning entrance of the temple’s northern corridor. A massive portal, composed of a lintel flanked by two serpent-columns, towers above her head.

She steps inside, the interior pitch-dark. “Mick, are you in there?”

Her voice sounds dampened. She reaches into her backpack, locates the flashlight she purchased earlier, and enters the dank, limestone chamber.