Lord Hastings smiled as he saw the eager looks upon the faces of both.

"Well, we have a little work cut out for us," he replied quietly.

"Hooray!" cried Frank.

A pleased expression fluttered across Jack's face, but he gave voice to
no exclamation; he was never as effusive as his chum.

"I'm glad you're pleased," returned Lord Hastings. "Yes, we shall see
active service, at once."

"When do we start, sir?" asked Frank, his face shining.

"In the morning."

Frank's face fell.

"I was in hopes it was to-night," he replied.

"Scouting, submarine or what?" demanded Jack.

"You will have to wait for an answer to that question," said Lord
Hastings. "In the meantime, it would be well this afternoon to get
whatever equipment you may need. Your other things, together with mine,
are at the bottom of the sea with the old D-16."

"And perhaps," said Frank slyly, glancing at Lord Hastings, "before our
present work is over we may know something of the mystery"--he lowered
his voice--"of the vanishing submarines."