Brave Old Salt by Oliver Optic

Somers was now entirely relieved from duty. He had delivered up the prize and handed the prisoners over to the proper officers. On the following day he went on shore to spend a few hours before the supply steamer sailed. On visiting the fortress, he received the astonishing intelligence that Mr. Pillgrim had escaped from the officer having him in charge, even before he had been placed in the casement appropriated to his use. Somers had cautioned the lieutenant to whom he had delivered him, of the danger of removing the irons, but his advice had not been heeded. The careless officer was now under arrest for his neglect of duty.

By none was this unfortunate event more deeply regretted than by him who had been the means of foiling the schemes of the traitor and handing him over to the custody of the government. Pillgrim had boasted that he would soon be at liberty. He was certainly a talented and a daring fellow; and to handle him safely, it was necessary to understand him thoroughly. Somers had a suspicion that the officer from whom the wretch escaped was bribed by his prisoner; but of course there could be no evidence on this interesting point.