They were awakened about five o'clock by a loud knocking on the door, and presently they heard the voice of Canfield calling to them.
"Wake up, boys!" he cried. "I have good news for you!"
"All right, let her go!" shouted Tommy.
"The pumps are working, and the water is lowering in the mine!"
"That's nice!" laughed Sandy.
"And we've found out what caused the sudden flooding," the caretaker went on. "It seems that a partition, or wall, between the Labyrinth and the Mixer mine unaccountably gave way. The Mixer mine has been flooded for a long time and, as it lies above the level of the Labyrinth, the water naturally flowed into our mine as soon as the wall was down."
"But what caused the partition to fall?" asked Will, opening the door for the admission of the caretaker.
"No one knows!" was the answer.
"If you look about a little," Tommy suggested, "I think you'll find traces of dynamite. Who discovered the break in the dividing wall?"
"A gang under the leadership of Ventner, the detective!" was the reply.