There was an explosive whump that made Monica cringe, followed by darkness and silence. Aimee looked at Alex, then dropped her eyes.

Alex turned back down the cave, his face a mask of stone. He knew that the small war Tank had been waging had been decided; he could already sense the outcome. “Let’s go.”

Matt walked close to Monica, whispering to her continuously. After many minutes he was rewarded with a smile, then a small laugh. It was many more minutes before they noticed the difference in the cave. It was almost sterile compared to the scuttling and crawling abundance of life they had seen in the outer subterranean world. The dripping mosses and glistening lichen ferns had disappeared. Not only was the cave devoid of life but it was unexpectedly dry and smooth.

“No moisture; that could be a good sign—means we’re headed for a drier atmosphere and hopefully the surface.” Monica was determined to remain optimistic.

“Excellent, now if we can just keep up this sprint pace for the next eight hours or so, in the dark, and stay ahead of the monster chasing us, we’ll be just fine.” Matt kept a good-humoured lilt to his voice in between his ragged breaths. But he, like the others, knew that at any moment they could reach another choke or find that the end of the tunnel had long since been iced over.

Alex was also formulating alternatives in the event they got to an impassable blockage. His major concern at present was the lack of cover afforded by the worn, smooth cave. If they were run down by the giant creature now, he didn’t like their chances of surviving in a stand-up fight when their only firepower was what he carried and a couple of grenades.

The grinding, pulverising noise was continuing from the way they had come, which meant they were still being pursued. Up ahead there was a slight narrowing of the cave and Aimee turned to Alex. “It’s bottlenecking, it can’t pursue us if the cave gets any narrower.”

Alex didn’t get it. How could the creature have first attacked them in much smaller caves, or for that matter, have made it all the way to the surface to attack Aztlan when it was of such an enormous size. There was no way it could get that hard shell into smaller caves. “Ms. Jennings, please scout ahead and everyone continue with the pace as is. I’m just going back to check on our friend and perhaps see if I can slow him down a bit.”

“I’ll come with you.” Alex could see a look of alarm on Aimee’s face.