“It was,” nodded Captain Gales.

“And I have not since been in your office, sir.  You know that of your own knowledge, and from what the marine orderly has been able to inform you, sir?”

“I am satisfied that you were not in thus office after you delivered the packet,” replied the Old Man.

“Then I could not have taken it from your desk, sir.”

“I am well satisfied of that,” assented Captain Gales.  “The only untoward circumstance is that the envelope was found in your quarters.”

“Then, sir,” Dave argued, “it is established that I could not have been the principal in the theft that was committed in your office this afternoon.  That being so, the only suspicion possibly remaining against me is that I may have been an accomplice.”

“No lawyer could have put that more clearly,” replied Captain Gales.

“Now, sir,” Dave continued, bravely, “if the important letter of instructions, or even if only the envelope had been handed me, is it likely, sir, that I would have hidden it under my mattress, when I might as readily have burned it or dropped it overboard?”

“Any clear-headed man, I admit,” said the Captain, “would have destroyed the useless envelope sooner than have it found in his possession.”

“The only possible use to which the otherwise useless envelope could have been put, sir, was to incriminate me.  Would I have saved the envelope and by so doing taken a chance that could only ruin me?  Of what service could the letter be to me, sir?  I could not take it ashore, sir, for instance, to dispose of it to the Mexican officials, who probably would pay handsomely to get hold of the American naval plans.  I have not asked for shore leave, sir.  May I ask, sir, how many officers received shore leave, and used it, after I returned to the ship?”

“Only one, Darrin; that was Lieutenant Cantor.”

Dave bit his lips; he had not intended to try to direct suspicion from himself to any other officer.

“So it might seem possible,” mused Captain Gales, aloud, “that Lieutenant Cantor might have obtained the letter and turned over the envelope to you to destroy, Darrin.  I am stating, mind you, only a possibility in the way of suspicion.”

“Lieutenant Cantor and I are not on friendly terms,” Dave answered, quickly.  Then once more he bit his lip.

But the Old Man regarded him keenly, asking:  “What is wrong between Cantor and yourself?”

“I spoke too quickly, sir,” Dave confessed, reddening slightly.  “I have no complaint to make against Lieutenant Cantor.  The one statement I feel at liberty to make is that an antipathy exists between Lieutenant Cantor and I. I would suggest, further, that Lieutenant Cantor, even had he stolen the letter, could have taken it only after his return on board.  So that he had no opportunity to carry it ashore, had he been scoundrel enough to wish to do so.”