Of course, we had taken the precaution to wait until immediately after a lightning flash before putting our helm down, and, as it happened, the next gleam did not occur until several minutes after we had tacked; the probability, therefore, was that the stranger would know nothing about our manoeuvre until the scene was again illuminated. The question that now interested us was--how would her people act when they made the discovery that we had shifted our helm and were standing in their direction? There were three alternatives open to them. First, they might follow our example--tack, and endeavour to escape to windward if they believed their vessel speedy enough to succeed. Secondly, they might haul their wind and enter the Gulf of Venezuela, along the shores of which there are two or three shallow inlets, in one or the other of which they might take refuge and anchor, in the hope of being able to defend their ship successfully against a boat attack. And, thirdly, if they were perfectly honest--of which we had our doubts--they might proceed steadily on their way, taking no notice of us and our movements. When we next got a sight of them the third alternative seemed to be their intention, for, so far as we could discover, they had started neither tack nor sheet; we therefore proceeded to edge down very cautiously and very gradually toward her, keeping her about a point on our lee-bow. Now we discovered that our task was not going to be nearly so easy as we had at first thought, for in the very light breath of wind that was then blowing--and which was wholly insufficient to keep our lower canvas "asleep"--the stranger undoubtedly had the heels of us, slipping along so fast, indeed, that within a quarter of an hour of tacking we were running off with the wind abeam and our weather braces checked, instead of being upon a taut bowline, as we had been at the beginning of the chase. Meanwhile the expected storm, though it had been brewing long, showed unmistakable signs that it was not going to keep us waiting very much longer, for the sheet--lightning was flickering almost incessantly, while a low, deep muttering of distant thunder occasionally made itself heard. The storm seemed to be working up astern of us, for presently a dazzlingly vivid flash of chain-lightning rent the darkness over our weather quarter, quickly followed by a deep, hollow, reverberating peal of thunder that rumbled like the echo of a seventy-four's broadside. Another and another quickly followed, each nearer than that which had preceded it; and presently, far away astern of us, we saw advancing toward us a sort of wall of vapour, the lower edge of which gleamed white and phosphorescent as the wind in it lashed the surface of the water into foam.