‘But it sounded,’ continued Walter, ‘as though it were in this room.’
‘That’s true.’
‘Then it must be his ghost; for there is no living being here except ourselves.’
Fenwick again flashes the light from ceiling to floor, as though to make sure of this. Then he says: ‘Kneel down, my lad. Place your ear to the ground, and listen.’
Walter quickly obeys; and for some minutes a dead silence reigns in the strong-room. The beating of his heart is all that Tiltcroft hears; and all that he is otherwise conscious of is that Fenwick’s ‘eye’ is watching the side of his face uppermost on the floor as he lies there listening. Their patience is presently rewarded. Their ears are filled with another cry, pitiable and more prolonged.
Walter springs to his feet. ‘It is there!’ he cries.
‘Below?’
‘Yes; directly beneath our feet.’
The detective begins to examine the flooring. Inch by inch the ‘eye’ wanders over the ground. An antique threadbare drugget is moved on one side; packets of papers, ledgers, and lumber are shifted from one corner to another. At last Fenwick lights upon a circular hole about the size of a crown-piece, scarcely an inch deep. ‘Ah!’ cries he, ‘now we are on the track.’ He takes from his pocket a penknife, scoops about, and turns up a ring attached to the floor. He puts his large muscular thumb into this ring, and gives a jerk. A patch three or four feet square in the boarding is detached. ‘A trap-door!’ cries Fenwick. ‘Stand clear.’
So it proves—a trap-door, which the detective quickly raises, revealing pitch-darkness in the opening.