“We must be close to the outside, or at least where the outside used to be before it iced over.” Alex felt they were in a race now, he mentally checked off his armoury—his rifle was gone but he still had his blades, and a single grenade. His propane cylinder was out and Aimee had lost her gun a long way back. Not much if it came to a stand and fight; but if it came to that in this enclosed space, he didn’t think they would last very long no matter what armaments they had. Best if the lights went out before that happened.

The tunnel terminated in another stone door, this one also of the magnificent red granite and polished to a glass-like finish. At one time the door probably slid open as silently and smoothly as any modern-day palace door; now it was locked. Not by stone or steel, but by a rim of blue ice crystals surrounding the entire perimeter.

“This is it. At least we will be out from the stone and we can get a proper reading of depth. I might even be able to get a signal out to home base.” Alex had reached around into his backpack and withdrew his small sonar device in readiness.

“How are we going to open it?” Monica was running her hand over the blue ice.

Alex could hear the suppressed excitement in Monica’s voice and took a step up to the door to test its weight and thickness and whether there was any give in the edges. It must have weighed several tons and without something to melt the surrounding ice was not going to move any time soon. Even combining his great strength with that of all the others he doubted they’d be able to do more than get red faces. The only option was to use his last grenade.

“Here’re the options. One, we can find another way to the ice. Means we’re going to have to double back, and we don’t know how far. It’s a pretty good bet to assume the creature hasn’t given up yet so we may run into it again. Also, I reckon all the exits will be as iced up as this one. Second option is we use the last grenade to blow the door. It will get the door out of the way, but not the ice. Further, it will alert anything in these caves as to exactly where we are. It also means we will have exhausted our last major defensive ordnance.”

Alex expected them to think over the option for a minute or two. However, Monica jumped right in.

“Blow it up. I’m not going to go back down into those black holes again.”

Alex recognised the panic in her eyes. Even if they escaped, it might be a long time, if ever, before Monica wanted to go caving again.