The lads were too stunned to say a word.
"I just wanted to teach you a little lesson," continued Lord Hastings. "In the future, perhaps you will neither fall short nor go beyond your orders. I ordered you to Gravesend. You should not have gone beyond."
"But Davis, sir?" exclaimed Frank.
"As long as you were here, apparently prisoners," was the reply, "I simply used you to advantage. Davis is a German spy."
CHAPTER IV.
STRANGE WARFARE.
It was the following night.
Clad in heavy oilskins, Frank and Jack stood in the bow of the large, high-powered motorboat as it sped down the Thames in the darkness. Not a light was visible anywhere and it was impossible to see a yard ahead. But in spite of this, the boat fairly flew over the water; for the strong hand of Lord Hastings was on the wheel and there was not a spot in the river with which he was not familiar.
"Whew!" said Jack, as he turned about to shield his face from the icy spray. "This is what I call taking a long chance, if you ask me."