The skin, then a layer of yellowish fat, was peeled back on both sides. Philadelphion explained that there would be little blood, because the flow ceases upon death. The incision must have pressed right down to the bone. Now, his assistants held back the flesh, one each side, while Philadelphion severed the ribs from the breastbone by sawing through the connecting cartilage. We could hear the saw. At this point there were gasps. Aulus was leaning forward with his hand pressed to his mouth, possibly to stifle cries of amazement; well, that was what he claimed afterwards. I did wonder if those discard-buckets were provided in case spectators threw up. Someone nearer the front did suddenly keel over in a faint; he was spotted by Chaeteas and unhurriedly laid out in an aisle to recover. When he came round, he stumbled from the theatre.

Squeamish or not, the rest of us were gripped. We watched Philadelphion carefully remove and inspect the heart and lungs, then other solid organs - the kidneys, liver, spleen and smaller items. He named each dispassionately as he handled it. Particular attention seemed to be paid to the stomach and the reams of intestine. Their contents were investigated, with predictable results. A couple more members of the audience remembered prior appointments and fled.

It was all dignified, all methodical. Anyone with a modicum of religious attendance had seen similar procedures with animals, though often conducted out of the direct line of vision of all except the gods. (When acting as a priest, you try to hide your mistakes.) The dissector here was completely open but he had the same manner - that formal reverence of an officiating priest as he inspects the innards of a sacrifice, looking for omens. His calm assistants pattered around as attentively as altar boys.

It was not gentle. Though not butchery, it was a muscular activity. Even to de-bone a chicken needs exertion. No one who had been a soldier would be surprised at the physical strength needed to open flesh and dismantle a human skeleton. Philadelphion had to hack and rip. Young men who had spent their lives poring over scrolls were visibly shocked.

They were more disturbed when we reached the part where the skull was sawn open and the brain removed.

Philadelphion completed the procedure fully without making pronouncements. He worked steadily. Once he had finished, he asked Chaereas and Chaeteas to replace the organs in the body and reassemble it for sewing up. While they did that, we all shifted in our seats, stretched our limbs and tried to recover our composure. Philadelphion washed his hands and forearms thoroughly then dried them on a small towel, as if politely preparing to eat dinner. Afterwards, he sat by himself, making notes.

This did not take long. His assistants removed the bowls and instruments, and pushed the table with the body to an exit door; I thought I glimpsed Petosiris the undertaker, with his mismatched assistants, Itchy and Snuffly, waiting outside to receive the cadaver. Chaereas and Chaeteas closed the door and took up positions there for the announcement of discoveries, still moving unobtrusively and as if they were minor guardian deities.

Philadelphion stood for his oration. He held his notes, though he only rarely referred to them. His manner remained calm and confident.

‘I shall give you my conclusions now. You are welcome to ask questions.’

Aeacidas, the big dissenter fidgeted abruptly. He was beside another, quieter man, also older than the students. ‘Apollophanes,’ whispered our young friend Heras, himself a much healthier colour now. ‘The Head of Philosophy.’ Aeacidas did not in fact interrupt; even his bumptiousness seemed to have been deflated by the clinical choreography.

‘Much of what I found was normal for a man of Theon’s age,’ pronounced Philadelphion. ‘The rib cartilage, for example, is beginning to coalesce into bone, which we know happens as the years pass. But there was no sign of disease in the organs, nor any significant encroachments of age. The heart and lungs clearly failed, but it is not possible to determine whether that was a specific cause of death or part of the process. I found nothing worthy of comment in the brain.’

There was laughter at that - not from Aeacidas, in fact, but from Apollophanes. His laugh was gentle, almost sympathetic. The Head of Philosophy enjoyed a joke, it seemed, but was not strident.

Philadelphion himself smiled. He had not intended to be witty, but accepted that his straight remark could be taken two ways. ‘The areas I consider significant are concentrated in the digestive system. The liver, for instance, is larger and heavier than it should be, and when I sliced it through, the internal structure suggested that Theon had been drinking hard recently. This could be an indication of anxiety. As his colleague, who knew him professionally and socially, I would not have described him as a devotee of Bacchus.’

‘More fool him!’ commented Aeacidas. Philadelphion ignored it.

‘The condition of the liver was not enough to cause death. In fact, my observations failed to find any explanation for what we would consider a “natural” demise. We have, therefore, to determine an unnatural reason. No violence had occurred. So did he, in common parlance, eat or drink something that disagreed with him? It is known that Theon went out to dinner last evening. Those of you on the front rows are particularly aware that I found evidence of a large, rich and varied meal having been eaten; the food was consumed over a period of time, some hours before the Librarian died.’

‘How can you say the time?’ demanded one of the note-taking students.

‘I could tell from the food’s state of digestion and position in the organs. If everyone else is prepared to take my word for it, I can talk you through it later, young man; come and see me privately -’ Most of us were quite prepared to skip the details. ‘I shall be weary this evening; I suggest tomorrow morning at the zoo.’

‘How much can you ascertain about the meal?’ one of the other young men asked. Philadelphion looked uneasy and shrugged.

Aulus stood up. ‘There is no need to speculate. Details of the meal are known, sir.’ He gave a full breakdown of the menu, adding, ‘It has been established that all dishes were eaten by more than one person, with no other diner suffering any ill-effects. Two of us, indeed, have a strong enough stomach today to watch your necropsy.’

‘And much wine was drunk?’ the second student asked him.

Grinning, Aulus scratched his ear. ‘We drank the quantities you would expect at a meal of that kind, given that there were visitors from overseas and an important invited guest. I would say Theon kept up well, though he did not outpace the rest of us.’

‘As far as you remember?’ quipped Philadelphion. Clearly he too had a sense of humour. Aulus acknowledged the comment with another relaxed grin, and sat down again. ‘Since he was the honoured guest, we presume Theon would have been served as much as he wanted. A witness says his behaviour seemed unexceptional. So if he regularly over-drank,’ Philadelphion suggested, ‘this was done in private. Secret drinking, particularly when it has not been the drinker’s prior custom, is to be regarded as significant. I referred earlier to Theon seeming preoccupied, and this would reinforce my remark that he may have been experiencing mental anguish of some kind. Why am I concentrating on this supposition? Because in his stomach and oesophagus were intriguing remains - something he had eaten or drunk later than his dinner. I have saved samples, which I shall be discussing with our botanist colleagues. It is plant material, apparently leaves, and perhaps seeds. I am qualified to comment on the circumstances, inasmuch as we at the zoo examine animals - our own or those that are brought to us - animals that die when they have eaten poisoned feed. I recognise similarities.’