“Up she comes!” said Henri.

The slab was lifted high enough to give a chance for shoulder pressure, and the rest was easy, for when once out of its setting the stone had no great weight.

The lanterns revealed the fact that the workers had been rightly directed up to the minute.

The oak cover was there, and also the iron ring. Through this ring the boys shoved the bars and pulled the cover away from the opening.

The stone steps were there; somewhat crumbly, but there. The directions were verified to the finish.

“Don’t rush in there until you give the fresh air a chance to go first.”

Reddy knew a lot of things that he had never learned from books.

But now it was Henri who was getting impatient.

“It ought not to take long for the tunnel to clear, and, what’s more, we are going to get out of sight before daylight.”

Daylight was rapidly approaching.