"Yes. What could it have been?"
"You've got me, but it's heading toward the open sea. Great Scott! Maybe it's an enemy."
"An enemy?"
"Yes; you know how anxious the Germans are over this submarine business. Maybe this fellow has been spying about. May be going to report to a German submarine out there some place."
"Think we had better follow and have a look?" asked Jack.
"Believe it would be a good idea. Let's go."
Without another word, Jack brought the boat about and headed after the one that had so recently dashed by them. In the darkness ahead there was nothing to be seen.
"Like looking for a needle in a haystack," Jack called to Frank.
"That fellow can't be up to any good," declared Frank. "He showed no light and was going in a terrible hurry. There's something up."
"Does seem that way," agreed Jack.