As they watched they saw that, having crossed the lawn, the four men entered a meadow adjoining, and they then recognised the figures of Drost and Ortmann with two strangers. They all walked straight to the corner where stood an old cow-shed, and into this they all four disappeared.
For a full half-hour they remained there, Kennedy and his well-beloved crouching beneath a bush in wonder at what there could be in the cow-shed to detain them so long.
The shed was at the base of a high wooded hill. Away, at some distance on the left, the railway-line entered the great tunnel which pierced the hill, and through it ran one of the most important railways from the Midlands to the East Coast.
The reason of their long absence in that tumbledown cow-shed was certainly mysterious. The lovers strained their ears to listen, but no sound reached them.
"Very curious!" whispered Kennedy. "What, I wonder, should detain them so long? There is some further mystery here, without a doubt.
Something of interest is in progress."
Suddenly, all four men emerged from the shed laughing and chatting in subdued tones. Drost was carrying his hat in his hand.
They pa.s.sed within ten yards of the lovers, and as they went by they overheard Drost say in German: "To-morrow night at 11:30 a heavy munition train will come through the tunnel. Then we shall see!"
And at his words his three companions laughed merrily as they walked back to the house.
Kennedy and the popular revue artiste--the girl whose name was as a household word, and whose songs were sung everywhere--crouched in silence watching the men until they had disappeared through that long French window opening on to the lawn.
Then, when they were alone, Kennedy said in a low voice:
"There"s more going on here, Ella, than we at first antic.i.p.ated--much more! I wonder what secret that old shed contains--eh?"
"Let"s investigate!" the girl beside him suggested eagerly.
Five minutes later they emerged from the shadow, and hurrying quickly across the gra.s.s, entered the old tumbledown shed, whereupon Kennedy switched on his electric torch, when there became revealed a wide hole in the ground, which sloped away steeply in the darkness.
"Hulloa! Why, here"s a tunnel!" exclaimed Kennedy in surprise.
"They"ve been down there, evidently! I wonder where it leads to?"
Then, as they both glanced around, they saw a thin, twisted electric cable containing two wires which led from a cigar-box on the ground in a corner away down into the tunnel. Kennedy lifted the lid of the box, and within found an electric tapping-key with ebonite base and two small dry cells for the supply of the current.
"Now what can this mean, I wonder? Some devil"s work here, without a doubt!" he said. "Let us ascertain."
Together the pair carefully descended into the narrow tunnel that had been driven into the side of the hill, evidently by expert hands, for its roof had been sh.o.r.ed up along the whole length with trees cut from the wood. Away along the narrow pa.s.sage they groped, finding it so low that they were compelled to bend and creep forward in uncomfortable positions until they came to a sudden turn.
Whoever had constructed it had also succeeded--as was afterwards found-- in cleverly disguising the great heap of earth excavated. He had also probably misread his bearings, for at one point the subterranean gallery went away at right angles for about fifty yards, until there--where the atmosphere was heavy and oppressive because of lack of ventilation-- stood several petrol-tins. To one of them the end of the cable leading from the unsuspicious cow-shed had been attached.
As they stood staring at the petrol-tins a sudden roar slowly approaching sounded directly overhead--a heavy rumble of wheels. Then it died away again.
"Hark!" gasped Ella. "Isn"t that a train? Why, we are directly under the railway-line running through the tunnel."
"Yes, dear. A touch upon that key up in the shed and we should be blown out of recognition, and the tunnel, one of the most important on the line of railway communication running east and west across England, would be blocked for months."
"That is what those devils intend!" Ella declared. "How can we frustrate them?"
Seymour Kennedy reflected for a few seconds, holding his torch so that its rays fell upon those innocent-looking petrol-tins at the end of the cunningly contrived sap. Then he took up one of them and carrying it said:
"Let"s get back, dear. We know the truth now."
"It is evident that they intend to blow in the tunnel from below,"
declared Ella, as they crept back along the narrow gallery.
"Without a doubt," was her lover"s reply. "Mr Horton, as he is known, took the house with but one object--namely, to cut the railway-line to the coast--the line over which so much war material for the front goes nightly. Truly, the Hun leaves nothing to chance."
"And my father is actually a.s.sisting in this dastardly work?"
"I"m afraid he is, darling. But so long as we remain wary and watchful, I hope we may be able to combat the evil activities of these a.s.sa.s.sins."
"I"m ready to help you always, as you know," was the girl"s ready reply.
"But it grieves me that father is so completely German in his actions."
"It is but natural, Ella. He is a German. If he were English, and lived secretly in Germany, he would act as an Englishman. All enemy aliens should have been interned long ago."
Ever and anon, on their way back to the opening, they both stumbled upon the wire, while Seymour, carrying the petrol-tin, evidently filled with some heavy explosive, followed his well-beloved, who held the torch.
At last they emerged from the close atmosphere of the long, tortuous gallery that had been secretly driven to a point exactly beneath the railway-line in the very heart of the hill, and once again stood upright in the shed. Their clothes were muddy, and their hands and faces were besmeared with mud.
At last Kennedy put down the square heavy tin, the cap of which he very carefully unscrewed, and then examined it by aid of his torch, smelling it critically.
Taking from his pocket a strong clasp-knife he went back into the tunnel again for about fifty yards. With a swift cut he severed the lead which led away to the concealed tins of explosive, and bringing it back with him to the shed, took the severed end, unravelled the silk insulation of both wires, bared them by sc.r.a.ping them thoroughly with his knife, and with expert hand attached them to a detonator which he had taken from the tins concealed at the end of the gallery.
Having done this he put the detonator into the opening of the petrol-tin which, with its wire lead, he afterwards carefully concealed behind a heap of straw in the corner. He had taken care to replace the cable leading from the cigar-box exactly as he had found it, therefore, to the eye, it looked as though nothing had been touched. The cable ran into the underground pa.s.sage, it was true, but it returned back again into the cow-shed, and into the tin of high-explosive.
Kennedy, who knew something of mining, had noticed that half-way along the working a quant.i.ty of earth had been left for the purpose of tamping the gallery, in order that the force of the explosion should go upward, and not come back along the subterranean pa.s.sage. Before the Kaiser"s secret agents exploded the mine they would, no doubt, fill up the gallery at that point before completing the electric circuit.
It was evident that on that night the four men had made a final inspection before exploding the mine.
Therefore, quite confident in what they had achieved, Ella and her lover crept back, and away through the wood to where they had left the car.
At six o"clock on the following morning, the Victoria Hotel in Sheffield being always open, Ella entered alone, and ascended to her room.
Next evening at half-past seven she met her lover again in the Ecclesall Road, and he drove her out in the car away through Eckington and Clowne, to the wood from which they had watched on the previous night.
The weather was muggy and overcast, with low, heavy clouds precursory of a thunderstorm.
There was plenty of time. The attempt would probably be made at half-past eleven when the munition train pa.s.sed through, it being intended to explode the whole train as well as the mine in the heart of the tunnel, so as to produce a terrific upheaval by which the tunnel would be blocked for, perhaps, a mile.
Arrived at the edge of the wood, in sight of the lawn and house beyond, soon after ten o"clock, the lovers sat together upon a fallen tree conversing in whispers, and awaiting the result of the counterplot.
They were, however, in ignorance of what was transpiring within the house.
Truth to tell, Ortmann and Drost were at that moment in one of the servants" bedrooms upstairs, which had been cleared out, and where, upon a long table, stood a complete wireless set both for receiving and transmission.
"That fellow Kennedy is _here_!--and with my girl Ella!" gasped old Drost, who had just come into the room. "I"ve been across to the wood.
They"re actually here!"
"_Kennedy here_!" exclaimed Ortmann, his face pale in an instant. "How could he possibly know?"
"Well, he"s here! What shall we do?"