You can’t just sit here and wait. You decide to try to exit through the crack in the wall. Reluctantly leaving behind the big egg, you pocket the little one and wedge yourself into the crevice.

It’s a tight fit. You take a deep breath in an attempt to make yourself slimmer, and squeeze along. Even so, the rock wall catches at your clothes and scratches at your skin. For a brief moment you think you might get stuck. Your heart races and sweat forms on your brow.

You accidentally drop the torch. There’s no room for you to bend down to get it, so you continue without it. Your panic rises.

But after a metre or so, the crevice starts to widen. You see light up ahead and quicken your pace. Moments later, you emerge into a cavern.

It is an extraordinary sight. Stalactites hang from the ceiling and stalagmites protrude from the floor. Glowing lines of phosphorescence wind their way around these rocky structures and spread out along the walls and ceiling like a spider web.

You weave your way between the structures towards a tunnel at the far end of the cavern. Reaching it, you see that it is in fact two branching tunnels. One ends a short way ahead with a burst of daylight; the other is dark and gloomy with no visible end.

You are about to head for freedom through the short tunnel when you hear an indistinct whispering from the other one. It’s insistent and enticing, and strangely also seems to be inside your head.

If you want to investigate the sound, go here.

If you’ d rather just get out of here, go here.