“Then it’s time for it. Look here, I’m going to humbug them.”

Two more reports came, and, as the sound died out, Abel uttered so unearthly a shriek that Dallas felt it go through him in a shudder that chilled him to the bone.

“Bel!” he panted wildly.

“All right; did it sound natural?” was whispered back.

“Oh, you wretch!” whispered Dallas; and Abel laughed.

“They’ll think they’ve done for the dog and one of us,” said Abel softly. “Let them go on firing now for a bit, and then it will be your turn; only don’t squeak like I did.”

“I see,” said Dallas.

“You feel for something big, and when they’ve fired a bit more hurl it hard at the door, and then give a big groan.”

“All right!”

“They’ll feel sure then, and come up and begin to force open the door or the shutters. Then we must let them have it.”