Sometimes it seemed as though they were working upwards towards us, for we could hear a pick upon the stones; and so we waited there, as terriers wait for rats.
Through the remainder of the night we kept a watchful vigil, but about four o’clock in the morning the sounds ceased, and we concluded that they had completed their work—at least for the present. We waited an hour, and hearing no further sound resolved to open the flooring of the place wherein we stood and investigate.
This did not take us long, for as soon as we had cut through the cement we discovered, to our surprise, a wooden trap-door, and on pulling it up there was disclosed a narrow winding-stair in the thickness of the wall, leading down into the foundations of the house. The place smelt damp and musty, and the up-draught blew out the naked candle which the skipper held.
With Reilly holding his hurricane lamp, I descended the rough-hewn stairs, revolver in hand, prepared for any attack. At the bottom, which I judged to be on a level with the cellars, was a stout door that had been recently sawn through, for the sawdust was fresh, and there lay near by several candle-heads. The door had succumbed to the attack of our enemies, and the latter, having opened a way into the house, had evidently retired until the following night.
I chuckled to myself that we were forearmed against any secret attack, and then went forward, finding myself in a dark and narrow tunnel built round with rough stone and sloping downwards. In places the stonework had given way, and it was with difficulty that I squeezed past the fallen earth. Behind me came Reilly with the swinging lantern, the skipper following us close in the rear.
Scarcely a word was uttered by either of us. We were in a long, tortuous burrow that ran deep into the bowels of the earth. I had often read of subterranean passages made in ancient days to provide secret means of egress, but to traverse one was an entirely new and exciting experience.
Bennett and his accomplices had left some of their tools near the scene of their operations, thus showing that they intended to return. But the passage seemed never-ending, now ascending, and again descending sharply. In places water percolated through the roof and fell in cold showers upon us as we passed, while beneath our feet it ran in a small channel onward before us.
On we went, determined to trace the burrow to its end, when, having gone fully a quarter of a mile, I suddenly stumbled, lost my breath, and found myself falling through space into a Stygian darkness. A moment later I struck water, and with my hands frantically clutched at some slimy stones around.
Where I was I had no idea, for the darkness there was impenetrable. I only felt my body in water that was icy cold, and my hands slipping in the thick slime. I cried out loudly for help, and heard the skipper’s answering shout.
“Are you hurt, doctor?” I heard him inquire, and looking up I saw the light shining like a star far above me, and the form of my two companions peering down.