At this point, the Athenians have a

At this point, the Athenians have almost succeeded; references to the various constructions are sufficient evidence. This is what gives the interruption that follows its dramatic force: the Lacedaemonian Gylippus, who was sailing to the aid of Syracuse, hears about the status of the fortification(7.1.1) and moves quickly; he soon reaches Epipolae. When does he arrive? In case we were not paying close attention to the progress of the work so clearly indicated by Thucydides, he specifies the exact state of the works: His arrival happened to coincide with the critical moment(7.2.4) when the Athenians had completed, with the exception of a small portion next to the sea that they were still working on, a double wall to the Great Harbor; as for the remainder of the wall, above the circle wall and extending to the sea by way of Trogilus, stones had been brought in for the greater part of the distance; some sections had been left half-built, others were entirely completed. The danger to Syracuse had indeed been great. In this passage both the precise technical summary and then the comment, which does not lack emphasis, are remarkable; just as each separate detail is linked to the progress of the siege walls, the reversal itself is portrayed in terms of that progress. Only the intensity is greater to the extent that this progress will be more altered by it.