Lord Hastings gazed at the lad in surprise.
"Vanishing submarines!" he repeated. "And tell me, how did you know there were such things as vanishing submarines?"
"Why, Jack told me, sir," replied Frank.
"And how did you know it?" demanded Lord Hastings of Jack.
"I heard you and Mr. Churchill discussing it, sir," replied Jack.
Lord Hastings drew a long breath, evidently of relief.
"I didn't know we had been so indiscreet," he said, half to himself. "However, there is no harm done, for I know you boys are to be trusted not to repeat what you overhear. I'll tell you this, you two are among the very few who know that any of the German submarines have been accounted for."
"Then it is true?" asked Frank.
"Oh, it's true enough," replied Lord Hastings. "Perhaps a hundred of them have disappeared."
"And where are they, sir?" asked Frank. "At the bottom?"