"I hope you will succeed in capturing him," said he. "If you do, bring him here; I want a look at him. Here," he continued, as his clerk handed him a letter, "is a request that the provost-marshal will furnish you with a pass. Good luck to you, young man." Their business being finished, Frank followed the captain out of the cabin, and returned on board the Michigan. All that afternoon Frank was in a fever of excitement. He was impatient for the night to come, that he might know whether or not his attempt was to be crowned with success. A hundred things might happen to prevent it. The rebel might not come home, or the note might have been written with the intention of having it intercepted, in order to throw the one into whose hands it might fall on the wrong scent; or it might be written in cipher, and mean directly opposite to what Frank had supposed. But he consoled himself with the thought that he had done, and would still continue to do, all in his power to obey the admiral's general order, and if he failed, the blame would not rest with him. When the sundown boat was called away, Frank, after exchanging his uniform for a citizen's dress, and his cap for a tattered slouch-hat, thrust a revolver into his pocket, stepped into the cutter, and was soon set on shore. He walked directly to the office of the provost-marshal, which was in the hotel, and finding that officer at his desk, handed him the admiral's note, which ran as follows: "U. S. FLAG-SHIP BLACKHAWK, "OFF ALEXANDRIA, LA., March 20, 1864. "SIR:--Please furnish the bearer, Acting Ensign Frank Nelson, with a pass. He has important business to perform, which may detain him on shore most of the night, and it is absolutely necessary, for the successful accomplishment of his mission, that he should not be interfered with. Very respectfully, your obd't serv't., DAVID D. PORTER, _Rear Admiral_, Com'd'g Miss. Squadron. U. S. Provost Marshal, Alexandria, La. "Your business must be important indeed, judging by the language of this note," said the marshal. "You shall not be troubled." While he was speaking he had been writing an order commanding "all guards and patrols to allow the bearer the freedom of the city, as he was under special orders from the admiral, and must not be detained." "There," said he, after he had finished the pass and handed it to Frank. "That will take you through all right. You have my best wishes for your success."