Island was going to be more sensational than their previous one. They were sure of that.
"What'll we do about the door; leave it open?" asked Frank.
"No, we'll close it," decided Sammy, "that is if we can. Then the counterfeiters won't know we've been here, and they'll come back to their den, and we can help the police capture them."
"That's the way to talk!" cried Bob. "You're all right, Sammy!"
And then something happened. How it came about none of the boys knew, but Sammy admitted afterward that he must have touched one of the wires, or springs.
At any rate there was a blinding flash, a great cloud of white smoke shot out, and a loud boom.
"An explosion!" yelled Sammy.
"They're shooting at us!" cried Bob.
"Come on—get out of here!" gasped Frank, as they made their way through the blinding and choking vapor to where they imagined the secret door to be.
