As they did so their attention was attracted by a shrill whistle. Even as they located its source they saw two policemen hurrying toward them.
"You're under arrest," one of them announced as they came up to the four young men.
"For what?" Jack demanded, impatient at what threatened to be further delay.
"As spies in the employ of an enemy Government," the policeman answered, his hand near to the pocket containing his gun.
"You're wrong; we're Americans," the big leader of the four protested.
"That's a good one," the officer responded sarcastically. "Come along now, and tell it to the inspector in charge."
And despite their protests, and notwithstanding the fact that the fate of the world literally hung upon the passage of every minute now, they were led away to the police station and for two hours were held up there, submitting proofs and making explanations to show that they were, indeed, the special envoys of the American Government, and not the bandit gang which made its quarters in the abandoned house on the cliff.