Free Death in the Tunnel by Miles Burton

to Merrion. “Well, what do you make of it?” he asked.
    â€œI don’t know what to make of it,” Merrion replied. “Those two fellows are telling the truth, any one could see that. They couldn’t have made up a yarn like that, and stuck to it under your cross-examination. The lights were there, right enough. But what were they there for, and who showed them? We’ve got to have a look inside that tunnel, I can see that.”
    â€œYes, and we’ve got to satisfy ourselves how much can really be seen from the signal-boxes. I’ve been having a look at the calendar. On Thursday the sun set at 4.11, and the moon didn’t rise till after eight. The train entered the tunnel at half-past five, or very soon after. The man can’t have got into the tunnel much after quarter past, if those chaps saw the lights about the middle of it. But it would be pretty dark by then. He must have managed to slip past one of the signal-boxes unobserved, whatever the station-master says.”
    â€œIt’s a most extraordinary business, and I don’t begin to understand it. Let’s see your friend the station-master, and arrange for a personally conducted tour. But I’ll admit that the prospect doesn’t exactly fill me with rapture.”
    The station-master, still sceptical, put them in charge of a ganger, and the three began to walk towards the northern end of the tunnel. The cutting leading to it began almost immediately beyond Blackdown Station, and ran through the solid chalk. The walls of the cutting were very nearly vertical, and would have afforded a precarious foothold, even to an experienced rock-climber in daylight. In the dark, the ascent or descent would have been impossible. And unless it was dark, any one attempting it would have been in full view from the platforms of Blackdown Station.
    â€œIf any one got into the tunnel from this end, they must have walked along the line from the station, the same as we are doing,” said Arnold. “Well, that wouldn’t be impossible in the dark. But could they have got past the signal-box unobserved? That’s the point.”
    The signal-box, when they reached it, proved to be within a few yards of the entrance to the tunnel. The wall of the cutting had been recessed to receive it, and the box, which was fronted with glass, looked across to the opposite wall. The signalman, whom they visited, explained that at night both tracks were brightly illuminated by the lights within the box. He had himself been on duty from two to six in the afternoon on the previous Thursday. The evening had been clear, and the atmospheric conditions such that the entrance of the tunnel had been free from smoke. He was absolutely certain that nobody could have passed his box without being seen. Arnold and Merrion, seeing the conditions, were inclined to agree with him.
    Then came the exploration of the tunnel itself. Up till now there had been a path beside the down line, which, though uncomfortably close to the trains as they roared past, still afforded a measure of safety. But, at the entrance of the tunnel, the path ended. Thence it was necessary to walk on the permanent way, keeping a sharp look-out for trains, taking to the down line if an up train was heard, and vice versa. Here and there within the tunnel were refuges, caves dug out of the wall in which the three of them could barely crouch. More than once they were forced to seek shelter in one of these, when both an up and down train approached them simultaneously.
    The atmosphere was, in any case, positively suffocating, though the ganger assured them that conditions were exceptionally favourable. “Why, in some weathers you can’t see a flare a dozen yards away,” he said. “It’s tricky work then, I can tell you, gentlemen. You’ve got to keep your wits about you, for you know the drivers can’t see you any more than you can see them. And as to breathing,