In spite of the glorious work accomplished in those few hours Clif felt chagrined that he had, in the excitement of the struggle on the boat and under fire of the Spanish soldiers on shore, been forced to return to the flagship without the shell.  
He had thought considerably about it even during the stirring scenes through which they had passed. He had his own ideas about it and wanted to put them to the test.
 
Everything connected with it indicated to his mind some mystery, the solution of which would materially help the American forces.
 
In the first place, the way in which it was brought to his attention was unusual, to say the least. That a ship being pursued by a hostile craft should deliberately fire away from the pursuer and toward the land was peculiar, even for a Spaniard.
 
It was ridiculous to think that the shell had been aimed at Clif and his party, for even had it been broad daylight the American boat's crew would not have been visible to those on the Spanish ship. It was merely a coincidence that Clif happened to be where the shell landed.
 
"No," thought Clif as he revolved this in his mind, "that shot was not aimed at our forces. There was some other reason for firing it."
 
What that was he could merely conjecture, and he was not entirely clear in his own mind. That the mysterious purpose had been carried out to the satisfaction of those on the Spanish boat, Clif felt convinced, was evident from the fact that not another shot was fired.
 
Then the shape of the shell was an important factor.
 
"They are not using those round ones nowadays," thought Clif. "This one must be used for a special purpose. What that is, I'm going to find out."
 
The arrival of the Spanish soldiers and their peculiar actions before the little battle that followed also demanded explanation.
 
"They didn't know we were there," mused Clif, "or they would not have been so easily taken by surprise. Why were they there? Their capture of the Cuban courier was accidental, I'm sure. They were on some other mission."
 
Last of all, the theft of the ship's boat and the strange behavior of the two Spaniards who had taken it and whom Clif had been forced to overcome added a peculiar feature to the affair.
 
Taking it all in all, Clif felt that though they had bravely avenged the murder of the Cuban, and had brought the dispatches safely to the rear admiral, and with them a prisoner, still an important object had not been accomplished.
 
He meant to return for that unexploded shell in the face of every difficulty and put his ideas to the test. He had this purpose in view when he delivered with his own hands the dispatches to the rear admiral.
 
Rear Admiral Sampson glanced quickly over the papers after they were handed to him, and seemed highly pleased.
 
"These are of the utmost importance," he exclaimed. "With this information we will be the better able to act in conjunction with the insurgents when the proper time comes."
 
Clif knew the papers must indeed be of especial value from the rear admiral's manner, for it was decidedly unusual for an officer of such importance to unbend to that extent with an ordinary cadet. The rear admiral was evidently more than satisfied with the result of Clif's mission.
 
After a hasty examination of the papers, he turned to Clif, who had remained standing, and asked some particulars of his meeting with the Cuban courier.
 
Then Clif briefly but graphically told of his receiving the papers from the hands ............