Every few yards a smaller trench intersected this one at right-angles. None of these trenches had the palisades of sharpened outward-pointing sticks that the Turks would've installed if they'd been expecting an attack, and so Jack reckoned that these trenches did not belong to the camp's outer works, which had been put up to defend it from encircling armies of Christians. These trenches must, instead, be part of the assault against Vienna. The smoke and dust were such that Jack could not see whether the city was ahead of, or behind, him and the ostrich. But by looking at the way that the earth had been piled up to one side of those trenches, to protect the inhabitants from musketballs, any fool could make out in which direction the city lay. The ostrich was going towards Vienna, and so was Jack.