Suddenly a light gleamed for an instant before me, as if from a house in a grove of great trees upon a bank; and I knew that it came from the window of a ruined plantation-building, where our most advanced outposts had their head-quarters.  The flash revealed to me every point of the situation.  I saw at once where I was, and how I got there:  that the tide had turned while I was swimming, and with a much briefer interval of slack-water than I had been led to suppose,—­that I had been swept a good way down-stream, and was far beyond all possibility of regaining the point I had left.  Could I, however, retain my strength to swim one or two hundred yards farther, of which I had no doubt, and if the water did not ebb too rapidly, of which I had more fear, then I was quite safe.  Every stroke took me more and more out of the power of the current, and there might even be an eddy.  I could not afford to be carried down much farther, for there the channel made a sweep toward the wrong side of the river; but there was now no reason why this should happen.  I could dismiss all fear, indeed, except that of being fired upon by our own sentinels, many of whom were then new recruits, and with the usual disposition to shoot first and investigate afterwards.

I found myself swimming in shallow and shallower water, and the flats seemed almost bare when I neared the shore, where the great gnarled branches of the live-oaks hung far over the muddy bank.  Floating on my back for noiselessness, I paddled rapidly in with my hands, expecting momentarily to hear the challenge of the picquet, and the ominous click so likely to follow.  I knew that some one should be pacing to and fro, along that beat, but could not tell at what point he might be at that precise moment.  Besides, there was a faint possibility that some chatty corporal might have carried the news of my bath thus far along the line, and they might be partially prepared for this unexpected visitor.  Suddenly, like another flash, came the quick, quaint challenge,—­

“Halt!  Who’s go dar?”

“F-f-friend with the c-c-countersign,” retorted I, with chilly, but conciliatory energy, rising at full length out of the shallow water, to show myself a man and a brother.

“Ac-vance, friend, and give de countersign,” responded the literal soldier, who at such a time would have accosted a spirit of light or goblin damned with no other formula.

I advanced and gave it, he recognizing my voice at once.  And then and there, as I stood, a dripping ghost, beneath the trees before him, the unconscionable fellow, wishing to exhaust upon me the utmost resources of military hospitality, deliberately presented arms.