The forward march to Baktria would have taken the Greek army via Kushk, Maruchak, and Maimana along the route which is practically the easiest and safest for a large body of troops. It is the route followed by the Afghan Boundary Commission in 1885. Alexander, however, instead of resuming his march on Baktria, elected to crush another of the Persian satraps who was concerned in the murder of Darius and who ruled a province to the south of Herat. Crossing the Hari Rud he therefore marched straight on Farah (Prophthasia), then the capital of Seistan (Drangiana). Farah is considerably to the north of any part of the Afghan province of Seistan at present, but it was undoubtedly Alexander's objective, and the Drangiana of those times was considerably more extensive than the Seistan of to-day--a fact which will go some way to account for the exaggerated reports of the ancient wealth and fertility of that province. Farah is a great agricultural centre still, and would add enormously to the restricted cultivable area of Seistan, even if one allows for the effects of sand encroachment in that unpleasant region. Then occurred the plot against Alexander's life which was detected at Prophthasia, and the consequent torture and death of Philotas, who probably had no part in it. It is one of the many actions of Alexander's life which reveals the ferocity of the barbarian beneath the genius of the soldier. It was but the barbarity of his age--a barbarity for the matter of that which lasted in England till the time of the Georges, and which still survives in Afghanistan. After a halt in Seistan, probably whilst waiting for reinforcements, he struck north-eastwards again for Baktria. As it is generally assumed that the Macedonian force now followed the Helmund valley route to the Paropamisos, _i.e._ the Hindu Kush and its extension westwards, it is as well to consider what sort of a country it is that forms the basin of Helmund.