Hump Day Hook - July 17 - from Love in the Labyrinths #2 - The Unseen

I am one of many talented authors who share excerpts from their books and/or works-in-progress every Wednesday on Hump Day Hook. If you'd like to read some more enticing author hooks, please follow this link.
My hump day hook for the day - quite hot, this one - comes from my soon-to-be-released (August 1) contemporary romantic adventure, The Unseen (Book 2 in the LOVE IN THE LABYRINTHS series). I'm working on edits on this as we speak :-)

Here’s the blurb:
After gem smugglers murder three men, Kent Dunbar pretends to abandon his exploration of Vietnam’s Mountain River Cave, arranges to send the female assistants, including his new love, Rebecca Devereaux, back to the States, and enlists help from a team of Vietnam Veterans who served with his father.

Rebecca, shocked and hurt by Kent’s rejection, suspects something’s afoot. At the airport about to depart, she overhears some buff older men talking and realizes they’ve arrived to help Kent carry on his mission. Rebecca convinces her best friend, Amanda, to stay and when the flight is cancelled, the other assistant, Bunny ends up with them as well.

Passion ignites when Rebecca and Kent reunite and Amanda’s crush on explorer Tom quickly turns hot and heavy. While high maintenance Bunny is sent to a comfortable hotel, the two girls join the men on the adventure. But a killer’s pursuing Bunny, a handsome man’s about to sweep her off her feet, Amanda and Tom have been kidnapped, and the smugglers have acquired special powers. Will the adventurers be able to outwit the smugglers.

In this scene, Rebecca and Kent are following the gemstone smugglers, who kidnapped their friends Tom and Amanda. They've just found a vial the smugglers dropped in the mud and are checking it out...

“Holy crap.” Rebecca jumped back, blinking again and again to see if her eyes were tricking her. But still she saw nothing except empty space.
“What’s wrong?” Kent’s voice seemed to project from nowhere. “God, it feels like ants are crawling on me.”
“It’s not that—the powder made something happen.” Rebecca wanted to pinch and slap herself. “I can’t see you anymore."

If you'd like to download Book 1, Dangerous Descent so you'll be ready to read this one by release day, it's available on Amazon.