By the time they returned to their itinerary these people, who had

been strangers to start with, would have known each other very well indeed.

I needed to find them and study them myself. But, as dawn broke and my guts settled down at last, I went out to do one more piece of sleuthing at Olympia. Cornelius stirred, so I woke him and took him with me, as a treat. It turned out to be a bigger adventure than either of us expected.

It was barely light. All over the Empire slaves were rousing themselves, or being roused by short-tempered overseers. The most unlucky were stumbling grey-faced to hard labour in the mines, to do appalling, filthy work that would slowly kill them. The fortunate merely had to lay out a clean toga or tidy fine scrolls in a beautiful library. By far the majority would be gathering brooms, buckets, and sponges, ready to clean houses, workshops, temples, baths – and gymnasia.

Nobody barred our entry. Cornelius and I went through the palaestra porch into the colonnade. Anyone watching – as somebody must have been – would have seen my nephew bumbling after me, still with his eyes half-closed and clutching the back of my tunic like one of Augustus' anxious little grandchildren in that parade on Rome's Altar of Peace. Not that Cornelius would ever have been taken on an educational outing to see the Altar of Peace. All my sister Allia had ever taught her children was how to borrow from relatives. Verontius thought being a good father meant bringing home a fruit pie once a week; when he wanted to be a very good father, he bought two.

Cornelius needed wise adult attention or he would grow up like his parents. An onlooker would have seen me turn back to encourage the sleepy-head, tousling his hair affectionately. Someone may well have worked out that they could get to me through him.

A small band of workers in drab tunics was lazily raking down the dampened sand of the skamma. Wherever these slaves originated, they all had the same short build and swarthy features. A couple of torches flared in iron holders. Moths clung to the stonework nearby. Above the great courtyard, the sky was bleached but visible. It grew marginally brighter, as a hot Greek day began. People instinctively spoke in hushed voices, because the day was still too young for socialising.

At my signal, the slaves sauntered over and surrounded us.

I stretched, speaking slowly and hoarsely. "Don't you just hate this time of the morning? It's all whispers and croaks, and finding out who died in the night… I need some help, please. Will you tell me about when you discovered the murdered Roman girl?'

As I had hoped, they were open to enquiry. Most slaves love a chance to stop and talk. No one in authority had thought it important to order them to keep quiet on the subject. If he had known I was coming, the superintendent would have done, if only to annoy me.

They had found Valeria in a corner, with the sand in chaos around her as though she had tried desperately to escape on hands and knees. She was curled up defensively, blood everywhere. Blood and sand were clogged together on her clothing; she was fully clad which, the slaves agreed, suggested things had gone wrong quite early in her encounter with the killer. They had noticed that there was also dust on her dress, the kind of dust athletes used to cover their oiled bodies. I had seen it being applied the other day, flicked on with the palm of the hand and open fingers, so it hung in the air of the application room in clouds. On Valeria the sand was yellow, always admired for giving the body a subtle golden glow; not that that helped me much. Yellow was the most popular colour.

When informed, the superintendent had ordered the slaves to throw out the body. They had lifted her up and taken her to the porch, where they placed her in a sitting position (so she looked more lifelike and took up less room. They were still standing around there when Tullius Statianus turned up.

He started screaming. He squatted on his heels, weeping and staring. The superintendent heard the racket and came out from his office. He ordered Statianus to remove the corpse. After pleading for help, Statianus yelled abuse at the superintendent. Then he gathered up his battered young wife, and staggered off towards the campsite, with her in his arms.

"From what you say, Statianus was genuine. Not behaving like a man who had killed her?'

"No chance. He couldn't believe what had happened.'

That was interesting, though the unforced evidence of slaves would not count in a law court. I tried to elicit names of any palaestra members who might have been suspect, but the slaves abruptly lost interest and started drifting back to their work.

We should have left. You never do. You always hope one last cunning question will produce a breakthrough. You never learn.

Then I heard a gasp. I turned around, and my heart lurched. An enormous man had arrived without me noticing and grabbed Cornelius. Now he was squeezing all the breath out of the boy.

The huge wrestler was waiting for me to turn and see it happening. Now the muscle-bound child-crusher lifted my nephew above his shaved head, intending to hurl him to the ground. On hard, damp sand, it could be fatal.

The brute paused, leering.

He was in his mid-twenties, his absolute prime. Solid waist, huge calves, astounding thighs, monumental shoulders. Apart from a leather skullcap and boxing thongs, he was stark naked. His fabulous body was covered with olive oil – there was so much I could smell it – over which he had applied a thick layer of grey dust.

There was a wrestler, once, who stepped into the high road and stopped a chariot going at full pelt. This man could do that. He could stop the traffic one-handed, while eating a bread roll. Milo of Croton used to stand on a discus, holding up a pomegranate and defying all comers to remove the fruit from him. Only his girlfriend could do it, but she must have known where he was ticklish. Oh for a willowy wench with sensual hands who could give a therapeutic massage!

"Put the child down and let's talk!' Greek wrestlers do not talk. They glare, circle, grasp opponents in rib-cracking clinches, then slog away without time limits, until one hulk has thrown the other three times to the floor. Or until one is so badly hurt he cannot continue, Or, even better, one is dead.

The wrestler shook Cornelius, to make me even more anxious.

"He's a boy. He's not in your age class. Obey the rules!' My pleas were desperate. Held up at arms' length, with one mighty fist around both his ankles and another gripping the scruff of his neck, Cornelius was ashen, too terrified to whimper. "Put him down. He's done nothing. I understand what's going on – someone does not like my investigation and you've been sent to dissuade me. So put down the boy and murder me instead.'

The giant let out a bloodcurdling cry, a part of his act. He bent his

arms suddenly, elbows wide, as if about to hurl Cornelius across the skamma. The watching slaves stepped back nervously. From facing sky up to heading sand down, my nephew swung over like a rag, his chubby arms dangling. One free hand balled into a fist as if it was intentional and clocked the wrestler in the eye. The giant shook his head as if a wine-fly had flown at his lashes – but then, as you do, he just had to brush his eye with the back of his wrist, so he let go of Cornelius.

I leapt and captured the boy as he fell. To me, he was damned heavy. I managed to drop him to the ground fairly gently, though I wrenched my back. Then the wrestler knocked me flat. I sprawled on the sand; one-handed, I somehow shoved Cornelius out of danger. The wrestler kicked me away from him; I fell full length, eating sand.