end, getting shots of rock formations, the pools, the slime, and the millipedes. And they found more of the big, plodding beetles they’d seen earlier. Rudy said he thought they looked like dung beetles. In fact, he discovered three different species and took copious shots of them all. It was odd that none of the creatures appeared to be disturbed by their presence but rather seemed content to simply graze on the slime.
They gathered around one of the larger hot springs, observing the foam being generated by the slime.
“So what’s with all the foam?” Jack said.
“Well…” Rudy bent down to inspect the pool. “I think it’s hydrogen peroxide.”
Jack frowned. “How do you know that?”
“I’ve been working on a theory,” Rudy said. “Chemiluminescent reactions require hydrogen peroxide in order to work, right?”
“Chemi-what?”
“Chemiluminescent.” Rudy stood and pointed to the slime. “A chemical reaction that generates light. Glowsticks, fireflies, or our slime here. They all need hydrogen peroxide in order to glow.”
“Okay…”
“And hydrogen peroxide is produced naturally in most organisms as a by-product of their metabolic activity.”
“Of course it is.”
“So this slime, whatever it is, must be generating copious amounts of hydrogen peroxide to cause it to glow like it does. It’s called oxidative phosphorylation.”
“It’s kind of funny.” Jack shook his head. “I know you’re speaking English; I just have no idea what you’re saying.”
Rudy sighed. “If this slime is producing hydrogen peroxide and there are other microorganisms in the water that produce catalase, it would cause a chemical reaction.”
“Catalase?” Jack snorted. “Y’know, I slept through biology.”
“It’s the enzyme used to break down hydrogen peroxide into oxygen and water. So basically this could all be part of a symbiotic ecosystem that acts like a natural oxygen generator.”
Jack was starting to understand. “Oxygen… So that’s how the millipedes get so big?”
“It’s just a theory,” Rudy said. “But we got in here through that underwater tunnel. So if these caverns are sealed off from the outside and this slime is somehow giving off oxygen, it could easily raise the levels in here considerably.”
“Makes sense, I guess.” Jack nodded. “But my question is, why haven’t they found this slime in other caves before? Why only this one?”
Rudy shrugged at that. “Maybe it’s all the hot springs and geologic activity or something indigenous to this region; I don’t know. But this cave has an ecosystem that’s developed totally isolated from the rest of the planet. We have no idea how many other caves like this there are throughout the world. We’re just now discovering new species on the ocean floor and places we’ve never explored. Think about it—we know more about the surface of Mars than we do about some places on Earth.”
At that point Ben spoke up. “Hey, I think you guys might want to take a look at this.”
They made their way over to where Ben was shining his light on an object wedged in the rocks. Jack bent down for a closer look.
It looked like some type of segmented appendage—almost like a crab leg. But bigger than any crab Jack had ever seen.
Much bigger.
Rudy gently pried it loose and held it up in the light. The smooth, hard claw portion was about twelve inches long, black with a gray underside and curved down to a point like a sword from one of those old Sinbad movies Jack used to watch. The rest of the limb was segmented by two connecting joints and snapped off just past the second joint. Shreds of white tendons and pink muscle tissue dangled out of the jagged end.
Jack straightened up. “I don’t even want to know what that came from.”
Ben grunted. “Looks more like something that belongs at the bottom of the ocean.”
“It’s definitely some kind of arthropod.” Rudy turned the appendage over in his hands. “It’s gotta be at least eighteen or twenty inches long. That’d give this thing—whatever it is—over a three-foot leg span.”
“Probably closer to four,” Ben said. He stood and looked around. Then he pointed his light toward the wall of the cavern. “I say we keep moving. Looks like there’s another tunnel over there.”
“Fine, but I want to take this with me,” Rudy said. He got his wet shirt out of his pack, wrapped the appendage tightly, and stuffed it back inside. Then he produced a small plastic Ziploc bag of peanuts and dumped them into his pack. “I’m going to take a sample of this slime too. Just in case we actually make it out of here alive.”
They made their way through the passage Ben had indicated. The tunnel narrowed quickly and soon the slime had dissipated, leaving them relying again on their flashlights for navigation. The luminescent slime had given Jack a sense of space, but now the darkness seemed to huddle around them, making the tunnel feel even more cramped.
Finally the passage opened onto a wide, oval-shaped cavern. The walls swept upward, nearly vertical, giving the chamber a basin-like shape. This room, however, had no cheerful tendrils of glowing slime. It was completely dark, and the darkness felt even heavier than inside the passage.
Jack swept his light around. Ahead of them, twenty yards or so, the chamber curved slightly and extended out of their line of sight. Jack pointed the light back toward Ben and noticed that he was staring at the wall behind them.
“Jack, you might want to get a shot of this,” he said.
Jack turned to see markings scrawled on the surface of the rock with what looked like white chalk. They consisted of vertical lines with smaller lines protruding out at right angles in varying spots.
Rudy leaned in to view them. “Looks like the same kind of writing from your dad’s drawing.”
“We’re not the first ones here,” Jack said, digging out his camera to take some shots of the wall.
Ben stood with his hands on his hips. “Well, at least we know there’s probably another way out of here. I’m guessing whoever drew these came in by some other entrance.”
Jack zoomed in on the writing. “I wonder if these are the markings that Running Bear’s grandfather saw.”
They checked the wall for additional images but found none. So they spread out to inspect the rest of the chamber. Jack was searching along one wall where he’d discovered several side passages leading away from the main chamber. But they all looked too tight to crawl through. He was crouched down, shining his light into one of the tunnels, when he heard Rudy let out a sort of low groan.
Ben’s voice echoed in the dark. “What’s wrong?”
Rudy replied, “Just tell me this isn’t what I think it is.”
Jack scrambled up the rocks to where Ben and Rudy stood with their lights aimed at the ground. “What is it? What happened?”
In the dim circle of light Jack could see what looked like several long sticks lying in the mud and gravel at Rudy’s feet. They had a pale, ashen color that stood in stark contrast to the black rocks. So pale, in fact, that they seemed to glow in the light. Jack tried in vain to suppress a gasp.
“Bones?”
Rudy knelt down for a closer look. “Looks like a couple femurs and maybe some ribs.”
“They’re human, all right.” Ben’s voice sounded distant and detached.
“How do you know that?” Jack said.
“Because here’s the rest of him.” Ben swept his light to the side, where it fell upon a skull perched amid a small pile of other bones. Wide, hollow eye sockets stared back at them, and an open jaw gaped as if frozen in the midst of a silent laugh.
Additional arm and leg bones lay strewn within a ten- or fifteen-foot radius. Jack struggled through his revulsion to maintain a level of professional detachment, but there was something sinister he noticed in the discovery. Something familiar and darkly unsettling that he wasn’t sure he wanted to share with the others.
“He’s, uh…” Jack didn’t know quite how to put it. “He’s sort of… all over the place.”
Ben flicked his light up into Jack’s face, then back down at the skull. “Like the millipede in the tunnel. He’s
