And still I fancied I could hear something behind me, stalking. Every time I whipped around, the noise stopped. If this was Rome, I would walk casually around a corner and lie in wait, holding my knife ready. No; if I had been on a street, let’s be honest, I would have nipped into the nearest bar and hoped the fear would go away while I downed a beaker.

I had no knife this evening. There was no handy street corner and no bar. What I did find, quite suddenly, was half a dead goat.

It was lying on the path. It had been butchered - skinned and beheaded. The bisection was neat. There was a long rope tied around the half-carcass, stretched out along the path as though someone had towed the meat from a very safe distance. The bloody lure lay close beside a gate. That was damaged and stood wide open. The gate was supposed to close off the fencing where my two little girls had clambered, when they were trying to see down into the deep pit where Sobek, the crocodile, lived. Just inside the broken gate a long earthen ramp started, which gave the keepers access to him. At the bottom there was probably another gate. I felt sure now that if I went right down the ramp I would find that open too.

I did not bother. I knew the crocodile was not at home. He had left his compound. Sobek was now out here with me.

XXIX

I could not see him, but I reckoned he had me under very close observation.

I did wonder briefly why Sobek had not snapped up his half a goat. Perhaps something tastier was on offer. Now it could be me.

I gathered up the rope in loops and towed the meat with me. I have had better luggage. I kept remembering stories Philadelphion had told to thrill my daughters: Nile crocodiles’ persistence when trailing a victim; their great speed on land when they rose up on their legs and started running; their wiliness; their colossal strength; their vicious killing power.

Soon I found what Sobek really liked for dinner. The next horror lying in my path was a man’s body - though only part of it. Chunks of the corpse had been torn off. There was a lot of blood, so he had been alive during some of the agony. Sobek must have ripped off and gulped down the missing pieces. I wondered why he had left the feast. I guessed he would return for his prey as soon as his reptilian stomach rumbled. He had just gone to catch more.

Ominous scrapes and rustles still sounded close by in the darkness. The mighty beast must be circling around me. I thought of scrambling up the fence but Philadelphion had told us they kept Sobek in a pit because he could climb short distances. He was such a size he could certainly rear up quite high.

Then I heard a new noise - different, human, disconcerting.

I stared around, but saw nobody. Still, I had definitely heard a subdued whimper. My voice was hoarse: ‘Who’s there? Where are you?’

‘Up here . . . Help me, please!’

I looked up as instructed, and saw a distraught woman.

She was halfway up a date palm tree. Sheer fright must have propelled her up the tree; she had her arms and legs clasped desperately around the trunk, in the way boys shin up to collect fruit bunches, and was clinging on for dear life.

‘All right - I’m here.’ Not much comfort if she saw how scared I was. ‘Can you hang on?’

‘Not any longer!’

‘Right.’ I assumed she knew the crocodile was still about. No point stating the obvious. ‘Can you slither down?’

She could; in fact, at that moment her strength gave way, her grip on the trunk failed and she tumbled to ground level, landing at my feet. I helped her up, like a polite informer. She threw herself into my arms. It does happen.

Fortunately I still had one oil lamp, which facilitated a discreet inspection. My heart was pounding, but that was nervousness about Sobek. If she felt it, she was too distracted to notice. Her heart was pounding too - I could see it was, because her ruined gown had been flimsy in the first place; thanks to the hard stubs of palm trunk, her garments now hung in rags. She was covered with blood, where the sharp edges of vicious old leaf spurs had cut her. She must have disturbed insects as she fled up, and she may have known that palm trees are a favoured haunt of scorpions. None of that would have bothered her, because she had seen the part-eaten corpse that now lay at my feet. My guess was that the poor woman also witnessed exactly how the dead man had died.

I would have wrapped her in a cloak for comfort and modesty, but on a warm night in Alexandria only wimps wear cloaks. I had not been expecting to rescue distressed women. She had, if it’s relevant, dark eyes emphasised by cosmetics, masses of slithering dark hair that had come loose from various ivory hairpins, the figure of a still young woman who had never borne children and who took care of herself, pleasant features and a winsome manner. Only one piece of information was missing; she supplied it: ‘My name is Roxana.’ No surprises. Well, she was running around the zoo at night, looking spruce. She was not bad now, in this terrified state, and must have been exquisite when she first set out. No doubt she came to the zoo to see her lover, Philadelphion.

I understood why everything male at the Museion hankered for this beauty. Philadelphion, that silver-haired charmer, had all the luck. She was still young enough to be an extremely appealing prospect.

‘I am Falco. Marcus Didius Falco.’

‘Oh gods in heaven!’ she squealed in alarm, and immediately started to shoot back up the tree.

Olympus. My name may be ignoble, but it normally causes only mild contempt  . . . But at once I realised what had caused her to scramble for safety. I too looked around madly for a refuge. There was only one palm tree, and since Roxana’s strength had dwindled, she was not far enough up it this time to leave any room for me - not it I wanted to be out of reach of the giant jaws of the thirty-foot-long angry crocodile that had suddenly appeared out of nowhere and was rushing at me.

I whirled the goat on its rope, once, and chucked it. Sobek stopped to take a look. Then he decided I was better.

We had been told of his enormous length, but I wouldn’t volunteer to measure him with rulers. He stretched twice the distance of a fancy dining room, three times as long as mine at home. His four short, muscular, splayed legs had covered ground at a gallop in his first rush forwards; he looked happy to carry on at that speed if he had anyone to chase. I was not sure how long I could muster the same stamina -not long enough .When he opened his mouth, about sixty teeth adorned his yawn; they were all shapes and sizes, and all sharp-looking. The stench of his breath was terrible.

Roxana, more of a game girl than I had dared to hope, began to yell very loudly for help.

XXX

Sobek kept coming. My instinct was to run like Hades. ‘When crocodiles rise up on their legs, Julia, they can easily outstrip a man ...’

So don’t run, Falco; you’ll just encourage him ... I was about to scram regardless, when a shout stopped both of us. I leapt to one side. Distracted, the crocodile snapped his vast jaws, ripping off a large square of my tunic. Then he swung his great head towards the new arrival.

Thank Jupiter! Someone who was good with animals.

Out of the darkness burst my old friend Thalia, drawn by the noise. She looked rumpled even by her standards, but at least she had grabbed a spear and a heavy coil of rope. She threw me the spear. I caught it somehow. ‘Settle down, boy . . .’

Sobek might be pampered, but he despised endearments. He jerked from side to side, weighing up which of us to kill first. Excited voices were approaching; rescuers were unlikely to arrive in time. “We’re not going to lead him back home with a barley cake -Jump him, Falco!’

‘What?’

Sobek chose me.