'Ah,' said the senior partner, 'have you looked at the trap which gives on the old water-gate, White?'
'Old water-gate, sir!' cried White. 'What's that? I never heard of such a thing.'
'No, possibly not; it's been out of service for so many years,' replied Mr. Elliott; 'but it exists nevertheless, and we'll have a look at it.'
At this moment they were joined by Inspector Bird, and after a few words between the police-officer and Mr. Elliott, the party of four men and the scout went in search of the trap, the senior partner leading the way with a lantern, for which he had asked, in his hand.
At the farther end of the great storeroom a flight of winding stone steps led down into a huge cellar. Mr. Elliott went first, and threw the light of his lantern back to guide the others; for there was no hand-rail, and an ugly fall awaited anyone who might miss his footing.
'Why, sir,' said White, 'we never use this place; it's too damp. I've only been down here once before in the five years I've been with you, and there's neither door nor window to it.'
'Yes, White, there's a door,' replied Mr. Elliott; 'but it's in the floor, and that's what we're going to look at.'
Guided by the shine of the lantern, the party marched across the floor of the huge damp vault, and the senior partner paused beside a broad trap-door, and threw the light upon it. He gave a long, low whistle, and his brother said, 'Ah, first point to Slynn, Richard.'
'It is, it is,' said the latter, after a pause—'it certainly is.'
The trap-door was in two halves, meeting on a broad central bar slotted into the stones at either end. Each half was secured by a couple of big iron bolts running into sockets fixed on the bar. The right half was firmly fastened; the left half was unfastened at this instant; the great bolts were drawn back, and the sockets were empty.