The Diaries were only necessary to refute the rumours of poison, so they must be tied to a man whom these rumours are known to have affected. If they do not belong to Antipater, slandered by Perdiccas, they might concern his son Cassander, who was fiercely accused of murder by Olympias seven years after Alexander's death; another nine years after that, prominent members of Aristotle's school, also associates of Cassander, were attacked as Alexander's poisoners by his veteran officer Antigonus the One-eyed, then ruler of Asia. The two lines meet in Cassander, the favourite candidate as Alexander's poisoner. Perhaps he first circulated the Diaries as his answer; he could claim to have found them among Diodotus's papers, especially if Diodotus had been his father's aide. Alone of the Successors, Cassander both opposed Alexander's memory and needed to rebut the charge of his murder; he would be happy to cast Alexander's final month as a long debauch, while maintaining that he died of fever, not of something he had drunk. His friends from Aristotle's circle had a similar interest. Many disliked Alexander, not least for murdering their fellow-philosopher Callisthenes, and although there was no truth in Antigonus's answering slander that Aristotle poisoned his royal pupil, its memory lived on for five hundred years and was even held against the Aristotelian school by the Roman emperor Caracalla. The philosophers too had an interest in an alternative account.

Among these Aristotelians none is more interesting than Cassander's associate Demetrius, who fled Athens under the slander from Antigonus that Aristotle had mixed the fateful poison. Demetrius was a prolific author; he fled to Egypt and wrote the earliest book on the new god Serapis, detailing the many cures which the god had brought about through dreams. Serapis's mention in the Diaries has always seemed an awkward intrusion; a man like Demetrius, acutely concerned with the detail of Alexander's last days, might have inserted the name of the new healing god whom he championed so fervently in place of an unfamiliar Babylonian deity. Moreover, three of the four officers who are said to have consulted Serapis about the best treatment for Alexander are famous victims or enemies of Antigonus, who encouraged the slander of poisoning against Demetrius and his master Aristotle; Cassander, too, had joined an alliance against Antigonus to defend or avenge these three high officers' maltreatment. Other details, the 'house of Bagoas', for instance, were known independently to Aristotelians in Cassandcr's circle. To remove the slander against themselves and Cassander, it is very possible that they published or elaborated Diaries in the name of the regents' secretaries. The Diaries' tone, dating and contents would fit their purpose neatly.

If the pamphlet began as Perdiccan propaganda and the Diaries were perhaps worked over by Cassander and his circle, the various causes of Alexander's death can only be judged on their merits, not on their authorities. Drink can be dismissed as the main cause, just as the ex-officer Aristobulus knew that it should; the Diaries are the only hint that Alexander drank more heavily before his death, and they were probably written by men who loathed him. It is probably irrelevant that one of his personal doctors wrote as an expert on drunkenness, though it is interesting that he believed in protecting against poison by the futile prescription of a regular diet of radishes. Fever seems far more plausible than drink. Alexander had been boating on the Babylonian canals where malaria had long been endemic and although his sudden decline after a week's sickness is not a common malarial pattern, the effects of his chest wound may have made themselves felt. He was, said Ephippus, 'melancholic'; it is an attractive, but mistaken, theory that the ancients' disease of melancholia was identical with malaria, whose symptoms it often shared, and Ephippus anyway meant by the word 'hot tempered'. This, rather, suggests poison, of a king who was 'unbearable and murderous .

However, there is no evidence that the officers conspired among themselves or with Antipater before Alexander's death. True, the hot and demanding march to Arabia was only a week away; the pamphlet also refers, tantalizingly, to names of the guests at Medius's party 'whom Onesicritus the royal helmsman refused to cite for fear of their revenge'. Onesicritus published his book within two years of the event, but the pamphlet's words do not entail that he openly mentioned poison. He may well have begun the stranger story, repeated later by authors who used him, that Alexander drank from the cup of Heracles, cried as if struck by an arrow and then collapsed. Others believed this without even accepting the poisoning rumour; so too may Onesicritus, but he may not have dared to mention poison any more than the guests, and thus only dared to record that something dramatic happened at the party. He was an officer and contemporary, but a most unreliable witness; he is the one support for the possibility of poison and naturally, his word is not enough.

Conspirators apart, the poison itself is technically implausible. In an age which lacked any clear concept of disease or of the dangers of bad food and water, it was understandable that sudden illness should be blamed so often on slow-acting poison, a cause which was only identified after a chain of mysterious effects had been seen to their fatal conclusion. But unless slow poisons are sophisticated they cannot be guaranteed to be lethal: an acid, for example, could have caused Alexander to 'cry aloud as if struck by an arrow' and then worked slowly inside him until it eventually punctured his stomach or burnt his vocal chords to stop him speaking, but it is very doubtful whether ancient medicine was acquainted with an acid of the necessary powers. The poisons of herbalists were swift and irremediable, whether hemlocks, hellebores or belladonnas, and except as an explanation of mysterious illness, a slow poison met no need in the poison-chests of ancient Greece. If Alexander had been poisoned, he should surely have been given a massive dose which was absolutely certain to kill him at once. And yet Diaries, pamphlets and official calendars insist that twelve days elapsed between Medius's fateful banquet and the death of the king.

It is hardly possible to escape this. The Diaries' detailed narrative is not quite explicit that for the last five days of his life Alexander gave certain proof of being alive; however, on 9 June the troops processed past his bed and saw, allegedly a slight movement of his head and eyes while the king 'made a sign to them', in a Greek word which most naturally means a gesture of the right hand. He said nothing; he lay motionless in bed; but this sign implies he was still alive and that no poison had been given to him as long beforehand as 29 May. There have been too many allegations of poisoning in history before the nineteenth century for Alexander's to survive this damaging contradiction in the case.

Those who are accustomed to the deaths of powerful men will not be surprised that Alexander's is a mystery which is hard to solve beyond all dispute. History here has often been repeated, but of the attendant mood and circumstances, there is more to be usefully said: Alexander had died, a man 'generally agreed to be of a greater nature than is given to a mortal'} his divine dress would never be worn in entirety again, and watchers, though spared a march to Arabia, were left frightened and bewildered in a land very far from home. Outside the royal bedroom, nobody was sure what had happened; when the end was announced on 10 June, an ominous darkness fell on the battlements and broad streets of Babylon. Men strayed through the city, not daring to kindle a light: it was not that their invincible god had died, but he had, so they said, 'departed from life among men' and himself a sun-like deity, he had robbed them of light as his soul ascended to a home among the stars. His soul was immortal, but his body lay exposed in the desolate halls of Nebuchadnezzar's palace, and while the common soldiers fretted for their future, officers were already rumouring their divine king's last words. 'When they asked him to whom he had left his kingdom, he replied "to the strongest". He added that he foresaw that his prominent friends would stage a vast funeral contest in his honour. Whether through fever or poison, Alexander had died unable to speak, so that all such remarks can only be treated as legends. But he was watching, his men believed, from the heavens, and within a week, the second of his two alleged last sayings was already proving more true than the first. The funeral contest had begun, but many years would pass before the strongest could be seen to have emerged.