Monica was standing on the bank looking downstream. She turned to Silex, not caring that she was staring into his face and blinding him with the bright beam of her helmet light. “Well, we need to follow that river and we don’t have diving equipment or a raft with us, so you’re right, we do build a boat—but not from rocks, Dr. Silex, from people. There is a caving style for travelling down streams to ensure everyone stays together in the dark. It’s called the Disney method—everyone sits one behind the other holding on to the person in front by their feet. We rope everyone’s waists together and create a set of human train carriages. We’ll also need an anchor—someone who is tied to the group but set about twenty feet back to act as an emergency brake. Usually they’re the biggest member of the team.” Monica turned to wink at Tank.

Tank smiled and said, “Shucks, I didn’t even have to volunteer.”

“We also need a driver; that’ll be me.”

Alex quickly overruled the caver. “Good idea, Ms. Jennings, but I’ll sit out in front this time. The team is going to be too heavy for you to steer and I’m better able to sustain impacts. However, I’d like you to be right behind me, guiding me and telling me what to expect.”

They all turned to look at the river. None of the team particularly looked forward to getting into the black water and floating into the impenetrable darkness that loomed ahead. However, everyone realised that going back would be even worse.

Takeda took a reading downriver with a portable echo distance display unit and spoke back to the group. “Straight run for about two miles then it either bends, dips or stops. No narrowing I can detect.”

“OK, people. We travel the straight distance and stop for rest when we get to the bend. Let’s keep moving.”

Monica wound the soft rope around Alex’s waist and then left a vacant loop for herself to climb into. She looped in Matt, Mike and then Aimee. Takeda went next, then Silex and twenty feet back, Tank as the anchor man. Tank had already removed a small collapsible grappling hook from his pack and tucked it and its rope tether into his front suit pouch. They were ready.

If it wasn’t for Alex leading the way, they may have all hesitated a few minutes while working up their courage. As it was, before they had time to think he was wading into the water, and all being tied together, they had to follow.

Rocks moved; then more. A low groan emanated from under the rubble. A large flat piece of stone flipped over like a door opening and a black-clad figure sat up.