At such a juncture, a man in a dripping diving-suit entered and pulled off his helmet, after what had evidently been a hasty trip from the land through the entrance and up again into the harbor. As he approached, Del Mar saw that the man's hand was bound up.
"What's the matter?" demanded Del Mar. "How did you get that?"
"That fellow Jameson and the girl did it," he replied, telling what had happened in the cave. "Some one must have given them one of those new searchlight guns."
Del Mar, already ugly, was beside himself with rage now.
"Where are they?" he asked.
"I saw them go out to the yacht of that Professor Arnold."
"He's the fellow that gave her the gun," almost hissed Del Mar. "On the yacht, are they?"
An evil smile seemed to spread over his face. "Then we'll get them all, this time. Man the submarine—the Z99."
All left the office on the run, hurrying around the ledge and down into the open hatch of the submarine. Del Mar came along a moment later, giving orders sharply and quickly.
The hatch was closed and the vessel sealed. On all sides were electrical devices and machines to operate the craft and the torpedoes—an intricate system of things which it seemed as if no human mind could possibly understand.