“About half a mile or so up there is a tunnel,” said Julian, pointing past Jock. “The lines come from there and run here, where they break up in many pairs — for shunting and so on, in the old days, I suppose, when this place was used.”

“Let’s go up the lines to the tunnel,” said Jock. “Come on. There’s nothing to be seen here. Let’s walk up to the tunnel.”

“All right,” said Julian. “We may as well. I don’t expect we’ll see much up there either! I think these spook-trains are all a tall story of old Sam’s!”

They left the little hut with its forlorn candlelight, and made their way round the yard again. Then they followed the single-track line away from the yard and up towards the tunnel. It didn’t seem to matter walking on cinders now, and making a noise. They walked along, talking in low voices.

And then things began to happen! A far-off muffled noise came rumbling out of the tunnel, which was now so near that the boys could see its black mouth. Julian heard it first. He stood still and clutched Dick.

“I say! Listen! Can you hear that?”

The others listened. “Yes,” said Dick. “But it’s only a train going through one of the underground tunnels — the noise is echoing out through this one.”

“It isn’t. That noise is made by a train coming through this tunnel!” said Julian. The noise grew louder and louder. A clanking made itself heard too. The boys stepped off the lines and crouched together by the side, waiting, hardly daring to breathe.

Could it be the spook-train? They watched for the light of an engine-lamp to appear like a fiery eye in the tunnel. But none came. It was darker than night in there! But the noise came nearer and nearer and nearer. Could there be the noise of a train without a train? Julian’s heart began to beat twice as fast, and Dick and Jock found themselves clutching one another without knowing it.

The noise grew thunderous, and then out from the tunnel came something long and black, with a dull glow in front that passed quickly and was gone. The noise deafened the boys, and then the clanking and rumbling grew less as the train, or whatever it was, passed by. The ground trembled and then was still.

“Well, there you are,” said Julian, in a rather trembly voice. “The spook-train — without a light or a signal! Where’s it gone? To the yard, do you think?”

“Shall we go and see?” asked Dick. “I didn’t see anyone in the cab, even in the glow of what must have been the fire there — but there must be someone driving it! I say, what a weird thing, isn’t it? It sounded real enough, anyway.”

“We’ll go to the yard,” said Jock, who, of the three, seemed the least affected. “Come on.”