“Ocelo’s brother is a security guard. He says the redhead entered the park just before closing but no one remembers seeing him leave. That deal you signed with Borgia. It was all bullshit. You’ll get your immunity after I’m found dead. Come on, we’d better get moving.”

They open the valves of their air tanks, verifying their regulators are working. Hoisting the BCD vest onto their shoulders, they approach the edge of the cenote.

Mick slips his fins onto his feet, then loops the rope around his arms and eases himself over the edge of the pit. The Mayans lower him quickly into the stagnant, cold water, then retrieve the rope for Dominique.

Mick positions his face mask and regulator, then turns his flashlight on and ducks his head underwater. Visibility in the chocolate brown, foul-smelling murk is less than two feet.

Dominique feels her limbs quivering as she dangles above the cenote’s dark surface. Why are you doing this? Are you insane? She cringes as her feet enter the chilly, algae-infested cesspool. Releasing the rope, she falls in, gagging at the putrid smell. She quickly adjusts her mask, then shoves the regulator into her mouth and breathes, cutting off the stench.

Mick surfaces, slimy strands of vegetation hanging from his hair. He attaches a length of yellow cord from his waist to hers. “It’s pretty dark down there. I don’t want us getting separated.”

She nods, removing her regulator. “What exactly are we looking for again?”

“Some type of portal along the southern face. Something that will allow us access into the pyramid.”

“But the pyramid’s a mile away. Mick?” She watches him deflate his BCD vest and submerge. Damn it. She returns the regulator to her mouth, takes a last look up at the moon, then follows him down.

Dominique begins hyperventilating into her regulator the moment her face hits the turbid water. She swims blindly for several seconds, her sense of direction failing her until she feels Mick’s tug. She descends another twenty feet, kicks hard, then sees the reflection of his light along the cenote’s wall.

Mick is searching the limestone facing, the geology of which is matted in thick vegetation. Using his light, he signals her to spread out along the wall to his right and poke and prod the dense growth with her dive knife.

Dominique removes the knife from her ankle sheath and taps the rock as she descends feetfirst along the limestone wall. Thirty feet down, her hand slips into a three-foot hole, her watch becoming entangled within the thick vegetation. Unable to gain enough leverage to free herself, she braces her fins against the wall to pull free.

A six-foot water moccasin lunges outward, snapping at her face mask with lightning speed before shooting past her into the murk.

It is all her wracked nerves can handle. Panicking, she races topside, dragging Mick with her.