“We’ll have to conserve our candles,” was Phil’s first remark after he and his two assistants, Dan Fentress and Donald Winslow, reached the foot of the stairway. “I haven’t any candlestick yet, but we can make one with some stiff clay as soon as we get to digging.”

“What kind of masonwork do we have to cut through?” asked Dan, stepping over to the south wall and proceeding to find an answer to the question for himself.

“It’s brick and cement,” Phil replied, anticipating the questioner’s move to answer himself. “Ordinarily it would be difficult to break even with a crowbar and a sledge hammer; but observe that large frost-crack running down from one corner of the window. Several of the bricks there are almost loose. We can start a hole in the wall by picking out those bricks. Then the work of enlarging the opening ought to be comparatively easy with the aid of this pick.”

As he spoke Phil took up the tool referred to, which he had stood up against the wall, together with the spade, shovel and hoe discovered by him on his first inspection of the cellar. It was by no means a delicate looking pick, and all three of the Marines who examined it agreed that it ought to withstand an extremely heavy leverage in the work before them.

“I figure that the man who lived here worked in that quarry, and that is the explanation of these tools,” Phil continued after his companions had examined the articles in question and satisfied themselves as to their serviceability.

“They are not exactly stonequarry tools, or at least they constitute a decidedly incomplete kit,” Dan remarked critically. “This isn’t much more than an ordinary garden outfit.”

“Well, anyway, they’re here for us to use,” Winslow put in; “so let’s get busy, for this candle is nearly half gone already, and we’re liable to run out of light if we don’t hustle. Here goes for a starter.”

He seized the pick and was about to transform his manifestation of energy into action, when Phil stayed him with this caution:

“Be careful, Winslow; no hard blows. Remember, there are guards within a few rods of this house, and any noises, even though they are muffled by cellar walls and masses of earth, are pretty certain to be investigated.”

“Very wisely said,” returned the young Marine with the pick. “I’m altogether too impulsive for a general. That’s the reason I’m a private and always will be. What shall I do, sergeant, begin a toothpick operation on the wall?”

“Yes, something o’ the sort,” Phil replied, smiling. “Jab the pick into that crack there and see if you can’t pry some of those bricks loose.”

Winslow did as directed, and was astonished on discovering with what ease half a dozen of the bricks came out.

“Fine!” exclaimed Phil gleefully. “Now, try some of that solid wall.”

Winslow did as directed. He was a powerful fellow—Phil had selected him as an aid for this reason. The pick stood the test and the wall fell away in bits. In less than an hour—estimated—a section of the wall three feet wide and nearly six feet high had been broken away, and the first candle was still burning.

“Everything’s going great,” said the young engineer of the enterprise. “The candles are going to last longer than I thought.”

“Shan’t we light two of them?” Dan suggested. “We can work faster, maybe.”

“No, not yet,” Sergeant Speed replied quickly. “We’ll have two or three of them going after we get the tunnel started a few feet.”

“Stick ’em on our hats?” inquired Winslow.

“No, we haven’t any way that I know of to fasten them to our hats. We’ll cut niches in the wall and set the candles in there. By the way, I’m going upstairs and get a couple more fellows down here to help.”

“We’ll have to have some fresh air before long,” said Dan. “First thing we know we’ll be asphyxiated—carbon-dioxidized, as it were. That fresh air upstairs won’t come down here unless forced down with a fan, or we manage to effect some kind of open-air vent through these walls.”

“I’ve been thinking of that,” said Phil; “and I have a scheme that I think will work first rate. After we get ahead with the tunnel a few feet, we’ll cut a hole straight up to the surface next to the foundation. We’ll keep the lights away from that hole, and stop our talking, too.”

Phil now left his two companions hard at work and ascended the stairway to report progress to his waiting companions and select two or three more assistants to help speed up the work in the cellar.