Having secured the true character of Hermocrates' preventive plan, we may now determine its place within the historian's concept. This is the first time that the categories of prospective success or failure on Sicilian soil, under which the campaign had been discussed in the assemblies at Athens, are superseded by a possible and unforeseen, albeit never executed, development, viz. the delay or even termination of the expedition before it can reach its target area. The literary detail dedicated to outlining the ramifications and minute subdivisions of the anticipated Athenian reaction to the enterprise proposed by Hermocrates forces the reader to add a new category to his expectation that inadequate planning will lead to failure: what may look like a predictable train of events can be interrupted and thrown off course by unforeseen factors, here consisting of bold planning on the opposite side. The mere possibility of such a deviation, even if it never turns into reality, is to Thucydides important enough to be introduced and elaborated upon in the historical work. This observation encourages us to look for and perhaps investigate similar crisis points in Thucydides' analysis of event sequences.Like other developments depicted in the History, the Sicilian War too offers a number of prominent occasions where the literary detail not only signals, as in the Athenians' death march toward the Assinaros river, the seemingly predictable fnal stage of failure and human suffering, but is also used to draw the reader's attention to an unforeseen situation, in which the train of events may switch tracks. A major example of this type of literary presentation is offered by the failure of the relief force which arrives from Athens under the general Demosthenes in July of 413. Having received advance information about the imminent arrival, the Syracusans attempt to win a pre-emptive victory over the Athenian feet (and army). The naval engagement, drawn out over three days, is a success. The train of events is described with great precision and technical detail (7.36-41). But the resulting Syracusan confidence receives a severe blow by the arrival of the unexpectedly huge relief force (which, on the opposite side, boosts the morale of the already despondent Athenians)