Philadelphion paused, to allow note-takers to catch up. While he spoke, his assistants stood completely still. Either he had rehearsed this, or they were already familiar with his approach. He spoke extempore. He was calm, audible and utterly compelling.

‘Erasistratus of Ceos also believed in research. He carried further the work of Heraphilus, who had learned that the arteries carry blood, not air as had been wrongly thought previously. Erasistratus identified that the heart works like a pump, which contains valves; he believed the brain to be the seat of our intelligence and he identified its different parts; he disproved the false idea that digestion involves some kind of “cooking” procedure in the stomach, while showing that food is propelled through the intestines by smooth muscle contractions. In his investigations of the brain, Erasistratus demonstrated that damage to certain parts would have a direct consequence on movement. For that, you will realise, it was necessary to experiment on live brains, both human and animal. His human subjects were criminals who were taken from the city’s jails.’

Again a pause for catching up - and for the reaction to subside. Aulus and his friend sat frozen in their seats. They saw themselves as tough young men. They went to the gym; they were up for an argument. Aulus had been an army tribune - though on peacetime duties. Still, as the bodily descriptions became more vivid, they grew more subdued. Everyone in the room was now envisaging old Erasistratus sawing open the head of some live convict and, while his victim screamed and squirmed, calmly observing what happened.

Undeterred by his audience’s cringes, Philadelphion continued: ‘Aristotle - the teacher of Alexander the Great, of Ptolemy Soter and of Demetrius Phalereus, the founder of the Museion - had taught that the body was a shell, housing the soul, or psyche. That did not excuse vivisection. But many of us believe that when the soul departs, the body loses all we regard as human life. That makes dissection after death legitimate, where there are reasons. I myself prefer not to countenance vivisection - experiments on the living, whether human or animal. Since that brief period when Heraphilus and Erasistratus flourished, all such experiments are seen as regrettable, or outright repulsive, by right-thinking people. Distaste for any kind of necropsy also rules. Cutting up our fellow-humans, we feel, lacks respect for them and may dehumanise ourselves. It is, therefore, a long time indeed since anyone conducted a “See for yourself” on a human corpse at the Museion.’

One or two people cleared their throats nervously. Philadelphion smiled. ‘If anyone feels he would rather not see for himself, leaving the room will be no disgrace.’

Nobody left. Some people may have wanted to.

‘So why is this case exceptional?’ asked Philadelphion. ‘We all knew Theon. He belonged to our community; we owe him special regard. He was physically fit, a lively debater, good for more years in his post. Perhaps of late he had seemed preoccupied. That could have had many causes, including illness, either known or unrecognised. But his complexion was good, his manner still zestful. I was startled to hear he had died, and I suspect so were many of you. Witnesses noted odd features when he was found. We can either bury him and think no more about it - or we can do him the service of trying to discover what happened to him. It is my decision to undertake a necropsy’ The two assistants stepped forward quietly. ‘We shall proceed,’ Philadelphion instructed, ‘always with respect and with gravity. Our actions will be conducted in a spirit of scientific curiosity as we enjoy the intellectual prospect of discovering answers.’

One of the assistants gently removed the cloth that had covered Theon s body.

First, Philadelphion did nothing.

‘The first procedure is close visual examination.’

Aulus turned to me and we nodded: this was the genuine body of Theon. He was naked - no modesty cloths here. Even from several rows back, his thin frame was instantly recognisable and so were his features and beard shadow. Unlike the undertaker’s false corpse, he still had his hair, thin, dark and lank. After their master’s inspection of the front, Chaereas and Chaeteas stepped forward and rolled the body for inspection of the back, then laid it down face-up again. The top of the head and the soles of the feet were scrutinised. An eyelid was pulled up. The mouth was opened and peered into for some time. Philadelphion used a spatula to hold down the tongue and look closer.

‘There are no wounds,’ he eventually pronounced. ‘I can see no bruises.’

‘Any asp bites?’ Aulus called out from our back row. He had a clear senatorial accent with a pristine Latin diction; his Greek had never been as fluent as his brother’s or his sister’s but he knew how to make himself heard well enough to start a riot. In the silence that fell you could have heard an asp slither. Every head in the room turned towards us. Everyone now knew there were two Romans in the room, just as insensitive as the cultured Egyptians and Greeks had always thought us. Aulus himself winced. ‘Because of the locked room, I just thought snakes ought to be considered,’ he mumbled, apologetically.

Philadelphion fixed the source of the crass interruption and replied with some coldness of tone that there were no snake, insect, dog or human bites. He continued methodically: ‘This is the body of a fifty-eight-year-old man, somewhat underweight and with poor muscle tone, but unmarked by anything that would explain sudden death.’ He touched the corpse. ‘Temperature and coloration imply that death occurred within the past twelve hours. We know, in fact, that Theon was alive until late last night. So! There are no answers yet. It will be necessary to dissect the corpse, if light is to be shed on what killed our esteemed colleague.’

At the words ‘esteemed colleague’ an elderly man on the front row snorted loudly. A large, jerky figure with unkempt hair, he lolled over two seats, arms and legs flung wide. His manner was proud; he took no notes; even from the set of his head we could tell he was watching as if he expected no good to come out of this.

‘Who is that?’ I asked Heras.

‘Aeacidas the Tragedian.’

Easy to get his measure. A long-time academic who did not expect to have to introduce himself and whose snide attitude had been apparent from the start. It was no surprise when he demanded, ‘Do you have a reasonable expectation that opening the body will solve any mystery?’

‘I have some expectation.’ Philadelphion spoke firmly. He was courteous but not prepared to be bullied. ‘I have hope.’

The tragedy expert did subside, which may have been unusual for him. It was clear he thought zoology a lesser discipline than literature; scientific experiments were just a low sport. But standing up to loudmouths often quells them, so Philadelphion still dominated the scene.

The second assistant had lifted away the cloth covering the instruments. Sharp knives, saws, probes and scalpels glinted; the last time I saw an array like it, an over-eager surgeon in an army hospital was threatening to amputate my leg. These were laid out amongst a pile of hemispherical bowls. Bronze buckets were also visible beside the plinth. Both assistants had quietly assumed aprons, though Philadelphion worked in his tunic, which was short-sleeved and unbleached.

He was handed a scalpel and, almost before the audience was ready, made a Y-shaped incision, cutting from both shoulders to the centre chest then straight down to the groin. He worked without drama. Anyone who expected flamboyance, and I fancied that included Aeacidas, would have been disappointed. I wondered how many times Philadelphion had done this before. In view of the questionable legality of these proceedings, I did not intend to ask. However, it was clear his two assistants were confident about their duties. He never needed to prompt them. Those zoo keepers knew just what to do.