The first thing Aimee noticed as she wriggled through the tiny tunnel was how easy it would be to get claustrophobic and lose it in such a confined space. You were continually banging your head, elbows and back on the jumble of fallen boulders. Some of the rocks were the size of houses, some were just rubble all pieced together like a giant’s jigsaw puzzle. Monica had placed a red chalk “X” on some of the rocks, indicating a weak spot or pivot point and these were to be avoided at all costs. Every time Aimee came across one glaring out of the dark her heart gave a leap at the thought of being buried alive, or worse, ending up crushed like Margaret.

Monica had said it was only about fifty feet, but she already felt she had been crawling for twice that—distance was hard to judge in such tight quarters. Perspiration ran down her face, creating more little streaks in the dust around her eyes and the air was already thickening from her hard breathing. It would be so easy to lose it in here.

She was fifth to go through, behind Silex, and mercifully he had slithered through rather quickly. The thought of him getting stuck and her spending the last few hours of her life trapped in a choke staring at Dr. Silex’s skinny legs was almost too much to bear. When she finally emerged into Monica’s waiting hands she felt such an unbelievable mixture of elation and relief that she almost burst into tears.

In no time Mike and Alex popped out of the hole and everyone gathered around waiting for Tank. Alex kept his eyes on the hole and said, “He’s struggling. He’s as strong as an ox, but about as flexible as a piano.” Alex got down on his knees and shone his torch down into the hollow. Tank must have dropped behind as he was still quite a way in.

Alex’s comm unit pinged. “I’m hooked up on something.” Alex turned to Monica. “He’s caught.” Monica immediately drew two soft elasticised ropes from her backpack and shot back into the hole. She reappeared moments later, leaving the two ropes trailing into the small opening.

“Yep, he’s wedged in about fifteen feet back. I’ve tied the ropes around his wrists. We’re going to have to give him a gentle persuasive tug. He’s ready for it.”

Alex pinged Tank. “On the count of three, big fella, give a push. One, two . . . three.”

The entire party pulled on the ropes but there was hardly any give. Then from deep within the boulder choke there was a very slight screeching sound like a truck putting on its air brakes, followed by a hollow grinding. Although there was no visible movement from the outside, they knew this would not be the case where Tank was stuck.