‘This is empirical research,’ I explained gently. ‘I seek evidence then draw conclusions from it. In this system, you are not given a set answer to which you must frame oratorical delivery. The objective is discovery, without preconditions or prejudice. A simple How? What? Where? and Wo? All to be answered before you can even start on Why?’

The lad still seemed worried. I was perturbed myself, by his narrow attitude. Far too many people shared it: the false belief that you could only ask questions when you knew the answers. I talked him through it gently: ‘I use libraries in my work in Rome. We have grand ones - Asinius Pollio’s public collection, the Library of Augustus up on the Palatine - and Vespasian is building a new overspill Forum in his own name, which is to have a Temple of Peace, alongside a matched pair of Greek and Latin libraries.’ There seemed no harm in mentioning that. It was not a secret. Vespasian’s programme of Roman beautification was to be world famous. ‘Now here I am in Alexandria. Alexandria and Pergamum have the best libraries in the known world - but, let’s admit this: who in Hades knows where Pergamum is? So for a man who is curious about all things, naturally in Alexandria I want to know about the Great Library’

‘This is independent of the suggestion that its Keeper was murdered? Even though you investigate such things?’

‘I cannot know whether the Library is relevant until I first find out what is normal there.’

‘So what are you asking me?’ Heras quavered weakly.

‘What have you noticed? How well does it all work?’

Heras looked shy and hung his head. No doubt he usually bluffed when he was quizzed by his tutor or his anxious father, but to me that night he told the sorry truth: ‘I am afraid I am rather lax. I do not go to the Library as often as I ought to, Falco.’

Well, he was a student. Helena sent me a look that said I should have known.

XV

Next morning, waking early was hard. But I had to beard the Head of the Museion and his colleagues at their morning meeting. It would be vital. I thought they were bound to discuss Theon’s death.

Besides, when I take against someone, I continue the pressure. I found Philetus, the Director, as savoury as steaming stable manure. I intended to fork him over until he squeaked.

Aulus was still snoring. So were most other people in the house.

Helena came with me. She was meeting Albia later to show the children the zoo, but as a thoughtful mother she would reconnoitre first.

‘Excellent woman. If Alcmene had been as careful, the infant Hercules would not have had that tricky moment jumping out of his cradle to strangle two snakes ... I can offer you another kind of zoo,’ I said. ‘There will be unbelievable wild beasts - it’s a human menagerie.’

‘The academics? They won’t let me in, Marcus.’

‘Stick with me, fruit.’ I took a linen napkin, made a sling, said I would claim I had damaged my hand and my wife was the only person I would trust to take notes faithfully or to keep it confidential afterwards. ‘Walk behind me. Sit very still. Don’t speak at any time.’

‘I am not a Greek woman, Falco.’

‘Don’t I know it! You are a handful, my darling, but the woolly intellectuals need not be told. If you can bear to keep your mouth shut, they may never realise.’ The chances were slim. She would burst out with indignation the first time they waffled unworldly twaddle. I beamed at her as if full of confidence. Helena knew herself; she looked wry.

‘They still won’t let me in.’

They would. Philetus had not arrived yet. This was a typical large organisation. The others were keen to do anything to get up their Director’s nose.

There was a good reason Philetus had not arrived. He was keeping aloof from unpleasantness: unpleasantness that he had caused. He had reported Philadelphion to the Prefect. Tenax and his sidekicks had come to arrest the Zoo Keeper for conducting an illegal human dissection. We found them on the steps of the Director’s building. The culprit was with them, standing with his handsome head thrown back, daring them to march him off.

I greeted the centurion easily. ’Gaius Numerius Tenax! And Mammius and Cotius, your excellent operatives. Smart turnout, boys!’ They had burnished their breastplates for this formal occasion. I do like to see trouble taken. The centurion had his greaves on this morning and gripped his swagger-stick as if he was afraid some naughty monkey might jump down from a gutter and snatch it from him. The monkeys were the ones wearing the Greek beards here, I was beginning to think. ‘Are we filling cells on this beautiful morning?’

‘There has been a complaint,’ complained Tenax. For once the complaint was not about me. (That could yet change.) Tenax spoke to me in an undertone, sharing his disgust with a fellow-Roman. ‘The prick in charge could have had a quiet word with me about it, but he just had to go straight to the Old Man, didn’t he?’

‘He’s a priest. No idea of form. Well, if you arrest the zoologist, Tenax, you must arrest me too. I was there when he sawed up Theon’s corpse.’

Tenax was fascinated. ‘So what did you think, Falco?’

‘I thought it was justified. It produced results - the Librarian had taken poison. We wouldn’t have known without unravelling his guts. I reckon you can assure the Old Man this necropsy was a one-off; view it as intended to be helpful. Also, go against it, and there may be bad feeling at the Museion, due to Theon’s popularity -’

‘What popularity?’

Helena giggled. ‘His colleagues will praise him like mad, hoping the same is done for them one day.’ Tenax took it well. He liked Helena.

‘Besides,’ I warned darkly, ‘this could escalate.’

‘What?’ Tenax still stood at Philadelphion’s shoulder, as if arresting him.

‘You know the Alexandria mob - taking a man into custody could blow up into a public order issue in five minutes.’

‘So what can I do, Falco?’

‘Go back and tell the Old Man you came down and assessed the situation. It’s your belief you should just caution the perpetrator, explain to him that such experiments are alien to the Roman tradition, get him to promise to be a good citizen - and effect a strategic withdrawal.’

Strategic withdrawal was not supposed to be the Roman army way, but Tenax saw Egypt as a soft posting, where the army kept out of trouble. ‘Can I say you concurred?’

‘Say whatever you like,’ I allowed graciously. ‘He will not re-offend.’

Tenax looked at Philadelphion. ‘Got that, sir? Caution, tradition, promise - and don’t do it again. Please don’t, or the Prefect will mince my nuts for offal gravy!’

Philadelphion nodded. He showed no reaction to the lewd remark, perhaps because he and his little dissecting knife were no strangers to testicles, of all types. The soldiers marched off smartly. We went indoors.

Philetus bumbled up soon afterwards. He looked astonished to see Philadelphion still at large. Of course he could say nothing, without admitting it was he who had grassed.

He found something else to be indignant about: ‘Do I spy a woman?’

‘She’s with me. Director, meet my wife. As a senator’s daughter, Helena Justina represents the glorious best of Roman womanhood. She has the rectitude and acumen of a Vestal Virgin. She is a confidante of Vespasian and holds the long-term admiration of Titus Caesar.’ Vespasian might be called a salt-fish salesman here, but his son and heir, Titus, was a golden boy in Alexandria. Good-looking young generals, hot from triumphs in the East, reminded them of their founder. Implying that Helena was the hero’s moll could only gild her prestige. I waved my sling. ‘She has my admiration and will take my notes.’

Furious, Helena was about to speak, but our unborn baby gave a fearsome lurch. I knew it from her expression so put an arm around her kindly. (It had to be a boy; he was on my side.)