"Jack! Jack!" he shouted.
But he was too late.
"Great Neptune, has the boy gone mad?" exclaimed Captain Turner, who had passed along the deck just in time to see Jack's dive. Regardless of sea etiquette, Billy grasped the skipper's arm and rushed into a narrative of the plan he and Jack had hoped to carry out.
"But Dusenberry was too quick for us, sir," he concluded.
"Never mind that, now," cried the captain, "that boy may be in danger."
He looked over the rail, which, owing to most of the passengers being busy below with their preparations for landing, was almost deserted. Billy was at his side. In the black motor-boat two men stood with their hands up. Alongside was a speedy-looking launch full of strapping big men with firm jaws and the unmistakable stamp of detectives the world over. Some of them were hauling on board the police launch Jack's dripping figure, which clung fast to the life-preserver. Others kept the men in the black launch covered with their pistols.
Half an hour later, when the passengers—all that is but Mr. Rosenstein—had gone ashore (the diamond merchant had been asked by the captain to remain), a little group was assembled in Captain Turner's cabin. In the center of it stood Professor Dusenberry, alias Foxy Fred, looking ever more meek and mild than usual. He had been seized and bound by the two disguised firemen as he threw the life-preserver, but not in time to prevent his getting it out of the port. Beside him, also manacled, were the two men who had been in the motor-boat and who, according to the Southampton police, formed a trio of the most daring diamond thieves who ever operated.
"I think we may send for Mr. Rosenstein now," said Captain Turner with a smile. "Only I hope that he is not subject to attacks of heart failure. Ready," he said, turning to Jack, who stood side by side with Billy, "take these and give them to Mr. Rosenstein with your compliments."
Jack blushed and hesitated.
"I'd,—I'd rather—sir—if you—don't mind——" he stammered.