He pulled up and the two of us stood, horror-stricken, rooted to the spot, looking into the little room.

I have said that Coates invariably closed the windows before leaving the house, but here the window was open. p.r.o.ne upon the floor was stretched the figure of a man!

He wore a light overcoat, and his hat lay under the telephone table--where it had evidently rolled at the moment of his fall. The poisonous smell was more apparent here than elsewhere; and looking down at the p.r.o.ne figure, the face of which was indiscernible because of the man's position:

"Why, Gatton!" I said in an awed whisper--"look!... he was speaking to some one!"

"I'm looking!" replied Gatton grimly.

Grasped rigidly in his left hand the fallen man held the telephone!

"We want gas-masks for this job," said the Inspector.

His words were true enough. I had already recognized the odor of the foul stuff. It was identical with that which, as we had come down from the upper floor of the Abbey Inn, had proceeded from the room wherein the mysterious sh.e.l.l had exploded. In a word my cottage was filled with some kind of poison-gas!

"We must risk it, anyway," said Gatton, "and find out who it is."

I nodded, sick with foreboding. Stooping swiftly, he succeeded in turning over the p.r.o.ne figure, whereupon I quite failed to restrain a hoa.r.s.e cry of horror....

_It was Eric Coverly_!

The fume-laden room seemed to swim around me as I looked down at the dreadfully contorted features over which was creeping that greenish tint which had characterized the face of Sir Marcus as I had seen it on the morning of the body's recovery from the hold of the _Oritoga_.

"Drag him out," said Gatton huskily; "he may be alive."

But even as we bent to the attempt, both my companion and I were seized with violent nausea; for the wisps of gray mist which still floated in the air were nevertheless sufficiently deadly. However, we succeeded at last in dragging Eric Coverly into the pa.s.sage. Here it became necessary to detach the telephone from the death-grip in which he held it.

I turned my head aside whilst Gatton accomplished this task; then together we bore Coverly out into the porch. At this point we were both overcome again by the fumes. Gatton was the first to recover sufficiently to stoop and examine the victim of this fiendish outrage.

I clutched dizzily at an upright of the porch, and:

"Don't tell me he's dead," I whispered.

But Gatton stood up and nodded sternly.

"He was the last!" he said strangely. "They have triumphed after all."

The man who had driven the car and who now stood in a state of evident stupefaction looking over the gate, where he had been warned to remain by the Inspector, came forward on seeing Gatton beckoning to him.

"Notify the local officer in charge and bring a doctor," said Gatton.

He turned to me. "Which is the nearest?"

Rapidly I gave the man the necessary instructions and he went running out to the car and soon was speeding away towards the house of a local physician.

I find it difficult to recapture the peculiar horror of the next few minutes, during which, half-fearful of entering the cottage, Gatton and I stood in the little sheltered garden adjoining the porch looking down at the body of this man who had met his end under my roof, in circ.u.mstances at once dreadful and incomprehensible.

Tragically, Eric Coverly was vindicated; by his death he was proved innocent. And by the manner of his death we realized that he had fallen a victim to the same malign agency as his cousin.

I have explained that my cottage stood in a strangely secluded spot, although so near to the sleepless life of London; and I remember that throughout the period between the departure of the man with the car and his return with the doctor and two police officers whom he had brought from the local depot, only one pedestrian pa.s.sed my door and he on the opposite side of the road.

How little that chance traveler suspected what a scene was concealed from his eyes by the tall hedges which divided the garden from the highroad! It was as the footsteps of this wayfarer became faint in the distance, that suddenly:

"Come along!" said Gatton. "We might chance it now. I want to get to the bottom of this telephone trick."

We returned to the door of the ante-room, and side by side stood looking down at the telephone which had only been extracted from the grip of the dead man with so much difficulty. The Inspector stooped and took it up from the floor. The deadly gray mist was all but dissipated now, and together we stood staring stupidly at the telephone which Gatton held in his hand.

To all outward seeming it was an ordinary instrument, and my number was written upon it in the s.p.a.ce provided for the purpose. Then, all at once, as we stepped into the room, I observed something out of the ordinary.

I could see a length of green cable proceeding from the wall-plug _out_ through the open window. The cable attached to the instrument which Gatton held did not come from the proper connection at all, but came _in_ through the window, and was evidently connected with something outside in the garden!

"What does this mean, Gatton?" I cried.

Evidently as deeply mystified as I, Gatton placed the telephone on the little table and fully opening the window, leaned out.

"Hullo!" he cried. "The cable leads up to the roof of the tool-shed!"

"To the roof of the tool-shed!" I echoed incredulously.

But Gatton did not heed my words, for:

"What the devil have we here?" he continued.

He was hauling something up from the flower-bed below the window, and now, turning to me, he held out ... a second telephone!

"Why, Gatton!" I cried, and took it from his hand, "_this_ is the authentic instrument! See! It is connected in the proper way!"

"I see quite clearly," he replied. "It was simply placed outside, whilst a duplicate one was subst.i.tuted for it. I observe a ladder against the shed. Let us trace the cable attached to the duplicate."

The ladder was one used by Coates about the garden; and now, climbing out of the window, Gatton mounted it and surveyed the roof of the lean-to which I used as a tool-shed.

"Ha!" he exclaimed. "A gas cylinder!"

"What!"

He fingered the green cable.

"This is not cable at all," he cried; "it's _covered tubing_! Do you see?"

He descended and rejoined me.

"You see?" he continued. "A call from the exchange would ring the bell in the ante-room here. This devilish contrivance"--he pointed to the false telephone--"is really hollow. The weight of the receiver hermetically closes the end of the tube, no doubt. But any one answering the call and taking up the duplicate instrument would receive the full benefit of the contents of the cylinder which lies up there on the roof!"

"My G.o.d, Gatton!" I muttered. "The fiends! But why was the contrivance not removed?"

"They hadn't time," he said grimly. "They had not counted on the death-grip of the victim!"

I heard a car come racing up to the gate, followed by the sound of many excited voices.

"At last we know where the gray mist came from," I said, as Gatton and I walked through the cottage to meet the new arrivals.