‘That sounds like rubbish.’

‘In my opinion,’ replied Thalia, ‘with which, when I put it to him properly, the Zoo Keeper agreed, a catoblepas is the same as the bloody big antelope I know as a gnu.’

‘A what?’

‘A g-n-u.’

‘Fabulous . . .’ I controlled my lungs, while wishing my breath could kill people. ‘So you pair were locked in debate about the origins of this suppositions creature for how long?’

‘Suppositions? Don’t come here with your big words, Falco.’

‘How long?’

‘Oh . . . about four hours,’ wheezed Thalia.

‘Don’t even begin to hope I’ll believe that.’

‘Falco, when I visit Alexandria, we always observe the customs of the desert. Perhaps we aren’t actually in the desert - but it’s close enough. So most of the time the Keeper and I were sitting cross-legged in my tent, having a respectable bowl of mint tea.’

‘Mint tea? Is that what they call it around here?’ I demanded caustically.

‘You do go on, Falco.’

‘I know you of old. You said most of the time. And the rest?’

‘What do you think?’

‘I think I feel sorry for Davos.’

‘Davos isn’t here to complain. Jason got a bit jealous - snakes can be touchy - but he knows it wasn’t serious and he’s all right about it now . . .’

‘When I first asked, you implied you hardly knew Philadelphion.’

‘Oh, did I?’

‘Don’t mess me about. I assume you have in fact known him well for years?’

‘Professional contact. Since before his hair went white.’

‘Roxana presumably knows that. So her suspicions of him were fully justified?’

‘Oh Roxana!’ Thalia grumbled. ‘Can’t she overlook a little bit of fun between old friends?’

‘Your “fun” got a boy killed by mistake.’

Then a shadow did darken Thalia’s face. Whatever her attitude to adult behaviour, she always had tender feelings for the young.

XLI

This was turning into a drear morning. Either people gave me the run-around or they came clean with stories I preferred not to know.

Next, I tracked down the lawyer. That was never going to cheer me up.

Only a fool would expect Nicanor to confess to anything. I knew if he did, there would be some tricky technicality that would get him off - probably with me looking stupid. I was spared that: he denied everything. According to him, he had never looked at Roxana and had no desire to beat Philadelphion to the librarianship. ‘Let the best man win, I say!’

I asked if he had any kind of alibi for the night Heras died. Again, I was wasting my breath. Nicanor declared he had been alone in his room at the Museion. Since he was a lawyer, he knew this was completely useless. His arrogance made me wish I had the key to the padlock on Sobek’s enclosure and a goat to lure the crocodile out to eat Nicanor.

That made me wonder who did have the key to the padlock. I wasted more time returning to the zoo to ask, only to remember I had been told. Philadelphion had one complete set of keys which was with him in Thalia’s tent when they were ‘drinking mint tea’. The other set hung in his office for the use of his staff. Chaereas and Chaeteas would have taken it when they visited Sobek to tuck him up for the night but they said they returned it. However, while Philadelphion was dallying the office had remained open, so anybody could have removed the keys again.

I asked about the half-goat. Food for various carnivores came from local butchers, generally unsold stock that was on the turn. Until use, it was stored in a shed, which was kept locked to prevent the poor stealing the meat for food. The key was on the same bunch that was kept in the office.

Disheartened, I went to dig out Aulus, to take him for a late lunch.

Helena Justina arrived with the same idea as I was walking to the Library. We all went together, along with Pastous, who took us to a fish restaurant he recommended. I calmed down on the walk there. There was really no need for Helena to send me that look of hers saying, Do not tell Pastous your opinion of lousy foreign fish restaurants. Which is: that you can never tell what anything is because fish have different names everywhere; that the waiters are trained to be rude and blind and diddle change; and that eating fish abroad is the fast way to experience whatever killing diarrhoea that town is famous for. Pastous was right, however. It was a good restaurant. It had enthralling views over the Western Harbour, where the mist had cleared today and we could see the Lighthouse. Among more mysterious names were recognisable varieties - shad, mackerel and bream.

While we were eating, Aulus and Pastous told Helena and me what they had managed to deduce from the old man’s note-tablets. They were full of complaints. Nibytas had left a haphazard jumble. His handwriting was particularly difficult. Not only did he run words together without spaces, but his cursive frequently deteriorated into little more than one long squiggly line. Sometimes, too, he used the papyrus back-side up.

‘You know papyrus, Falco,’ Pastous explained, as he spoke adeptly taking apart a fish he had called a tilapia. ‘It is made by cutting thin strips of reed, then placing two layers crossways; the first goes top to bottom, the next is placed on top of it, running from side to side. These layers are compressed until they coalesce; to make a scroll, sheets are glued together so each overlaps the one on its right. For preference, people then write on the side with the grain running sideways and the joins easy to cross. This is smooth for the pen, but if you reverse it, your nib constantly hits ridges. Your writing is rough and your ink blurs.’

I let him tell me all this, though in fact I knew it. I must have been enjoying my lunch so much it mellowed me. ’So Nibytas was becoming confused?’

‘Obviously had been for years,’ declared Aulus.

‘And could you make any sense of what he was doing?’ asked Helena.

‘Compiling an encyclopaedia, all the world’s known animals. A bestiary.’

‘Everything,’ elaborated Pastous in some awe, ‘from the aigicampoi (Etruscan fish-tailed goats) and the pardalocampoi (Etruscan fish-tailed panthers), through the sphinx, the androsphinx, the phoenix, the centaur, the Cyclops, the hippocampus, triple-headed Cerberus, the bronze-hoofed bull, the Minotaur, the winged horse, the metallic Stymphalian birds right up to Typhon the winged, snake-legged giant.’

‘Not to mention,’ added Aulus gloomily, ‘Scylla, the human-cum-snake-cum-wolf hybrid, who has a snake’s tail, twelve wolf legs, and six long-necked wolf heads.’

‘And no doubt the legendary catoblepas?’ I could show off too.

‘Whatever that is,’ Pastous confirmed, sounding as depressed as Aulus.

‘Most likely a gnu.’

‘A what?’ Aulus looked scathing.

‘G-n-u.’

‘G-n-obody has ever seen one?’

‘G-n-ot as far as I know’

Pastous remained serious. ‘The old man’s method is not acceptably scientific. Nibytas wrote a strange mixture; he included both true technical data and far-fetched nonsense. Made available to others, such a collection would be dangerous. The quality of the best parts would convince readers that they could trust the myths as factual.’

‘He evidently managed to pass himself off well,’ Aulus said. ‘He corresponded with scholars all over the educated world - even some old fellow called Plinius in Rome consulted him quite seriously, some friend of the Emperor’s.’

‘We had better warn him off,’ Helena suggested.

‘Do not be involved,’ Pastous advised her, smiling. ‘These dedicated scholars can be surprisingly unpleasant if you cross them.’

‘Did Nibytas ever snap?’

‘He became very worked up sometimes.’

‘Over what?’ I asked.

‘Small things he felt were being organised badly. He had high standards, perhaps the standards of a past age.’

‘So he made complaints?’