"While we were crossing the levee, and were in a dark and obscure place on the water front, I and the man with the wheelbarrow were set upon by a gang of roughs. The man who was wheeling the chest was knocked down and left unconscious, and I was bound, put in a closed carriage and brought here. Since that time my mind and body have both been shrouded in total darkness. Twice a day a negro has come and given me food, but I have seen nothing of either Whistler or Jurgens.
"However, I surmised the reason for my capture and detention in this place. My scoundrelly enemies wished to keep me in limbo until they had divided the treasure in the iron chest and got well away with their booty. Yet the time I spent here has not been altogether lost. I have cultivated my negro jailer. He would tell me nothing about my captors, nor why I had been captured, but he has promised to release me if I would give him $500. The last time he came with food I wrote a line to Cassidy telling him to pay over the money and ask no questions. The negro may get the money and then fail to carry out his part of the contract—but it was a chance I had to take."
"Isn't there any other way to get out of here except by the negro's aid?" asked Matt.
"I have had little else to do, while lying here, but turn such expedients over and over in my mind. I believe there is a way, Matt, providing we were armed with a crowbar. You will notice that the air in here is pure and wholesome—something you would not find in an air-tight vault."
"Matt noticed that, Townsend," returned Dick, "as soon as we landed in here."
"Well," pursued Townsend, "light another match, Ferral, and then watch the flame."
The match was lighted, held about a foot from the floor, and the flame was seen to be sucked sideways and downward, as though by a draught of air.
"There's a current of fresh air blowing through here," observed Matt.
"I noticed that the first time the negro brought my food to me," said Townsend. "He had a candle, and the flame of the candle, like that of the match, inclined downward and burned with a hissing sound as though fanned by a draught of air. I managed to roll about and investigate a little, tapping with my heels on the brick. There are crevices in the brick, over near the end of the vault, and I am sure that a little work with a crowbar would bring us either into the outside air, or into the shop below. But," and Townsend gave a grim laugh, "we have no crowbar; and, at the time I made my discoveries, I did not even have the use of my limbs."
"I've got a dirk, old ship," said Dick. "Give me time enough and I could dig through a stone wall with it."