Like a released pinball, the noise, the feeling, concealed in its ceiling of rock, shot away from Joshua with a velocity that made him dizzy. He knew it was something alive, and he knew it was travelling the whole length of the tunnel’s arc to the other entrance. There was a fraction of a pause, the fraction of a pause you expect when something thrown very hard is bouncing off its wall. The pause before it starts to come right back at you.

It was darkness, and it was rushing up the tunnel towards him like water forced through a pipe. Again he felt it first, reeling from its shock-waves as they pushed him back towards the entrance. But when he saw it, the natural black of the tunnel’s sunlessness being obscured by a deeper blackness impossible to comprehend, he remembered to breathe. As the black tide swallowed up the cab of the train, breaking over it like a wave, he turned and ran, his legs buckling and floundering beneath him. He had to make the entrance. There was no doubt about that at all. Instinct had told his logic to shut the fuck up and run, and instinct was telling him that if that wall of rushing blackness reached him before he reached the light, he would never feel the sun on his face again.

He ran like a child, making involuntary grunting sounds as his feet gouged the gravel, chin high, eyes rolling in their sockets.

When he fell out of the tunnel gulping for breath, the last thing he remembered was the darkness slamming into the entrance, as though the man-made arch described an invisible prison door. He was sure the darkness screamed with fury. No sound again, just a visceral reading of a ripping, hungry, scream.

Joshua was sure he had just preserved his sanity. The brakeman and conductor were not so sure. When they found Joshua, he was lying in the snow jabbering, and the best they could get out of him was the living rock.

He was taken home by road and was back at work in a fortnight. The conductor and brakeman filed a report, recalling that there had been a short power cut in the cab at the time that engineer Tennent ran. Yes, they had experienced temporary darkness, and yes, that’s probably what spooked him so bad. No harm done. Everybody safe, and a whole new joke to pass around the bunkhouses now that the one about Joe’s bear encounter had worn thin.

But even now, a whole year on, and after a hundred nudges and grins when Joshua walked into the canteen, each time the Corkscrews loomed he toyed with trading his railway pension for steady work in a hamburger joint.

Martell was still chuckling as the cab entered the tunnel. ‘Rock still livin’, Tennent? Can’t hear no breathin’.’