When I reached: it the door seemed to be jammed. It opened inwards. There was no lock, but, although the top edge gaped a few inches when I leant on it, the bottom stuck. I was trying to be quiet but in the end I forced it open a crack with a mighty, shove. Inside something must be lying right up against the door; it was still too dark to, make out much, though as I leaned close I was struck by old and disturbing smells. This place must be a fishing hut. It smelt as if pigs had been kept in; it but on the Rosius Gratus estate there were no pigs. Just as well, or disposing of bodies would have been easy, and there would have been no long trail of evidence to bring me here from Rome.

Whatever was impeding my progress would have to be moved bodily before I could enter. It felt like the dead weight of a filled wheatsack – or a body. But it was heavier than the body of a young girl. I looked around to see if I could break into the hut some other-way… Then I heard a twig snap.

I spun round. A man was standing fifty strides away.

I had only a glimpse before he plunged back into the thicket from which he must have emerged seconds earlier, clearly not knowing I was there. If it, was anyone but Thurius he had no need to flee. I yelled and, forced my tired limbs to race after him.

He must be better rested than me, but he might not be as fit. I hoped the slaves from the house would help to cut off his escape, but I was disappointed they must all have sneaked home for their breakfast, ignoring my orders to sit tight. No one answered my cry, and as we crashed through the wood no one rose in our path to intercept.

Everything went quiet. I had lost him somewhere.

`Thurius! The game's up. Show yourself and make-an end to this!'

No answer. I could hardly blame him. I was a stranger and he knew every inch of ground. He must be sure he could get away.

He had set off ahead of me working his way towards the track that led off the estate. I thought- I heard hoofbeats. I was stricken with visions of Thurius fleeing on horseback all the way to Sublaqueum.

There was no hope of shelter at the house. He, would realise his fellow slaves would want to establish their own innocence and pay him back for fooling them. Those who had let themselves ignore his strange behaviour over the years would be quick to denounce him now and if they, turned to violence, it wouldn't be the first time a newly discovered killer was bludgeoned to death by the people he had lived among

I crept through the bushes, aiming for the track. I was watching a pile of long logs, which could hide a prone man behind them. As I edged nearer, Thurius exploded from the undergrowth almost on top of me.

I jumped up, giving him' a mighty shock. He had just made a break for freedom, not realising I had worked so near. Before I could throw myself at him, I saw it would be too dangerous: he was now carrying a long axe.

He looked as surprised as me for a moment, but then he recovered angrily., Pulling up short, he growled and swung his weapon.

`Give up, Thurius -'

The blade sliced low, threatening my knees. I moved towards a tree, hoping to trap him into embedding the axeblade in its trunk. He snorted and made another wide, controlled sweep, this time at head level. The little knife I kept in my boot would be no match for this. I didn't even reach for it.

He looked as I remembered: nothing special. Unkempt, badly dressed, missing teeth: a typical rural slave. No more crazed than most passers-by on the streets of Rome. You would avoid knocking into him by accident, but you wouldn't look at him twice. If I was out late at night, and he made the offer casually, I might even accept a lift from him.

`I'm not alone. The Urban Cohorts are riding hard behind. Give yourself up.'

His only reply was another aggressive swipe of the axe, cutting off fine branches above my head. Immediately he followed up with a lower stroke the other way. In the army I had been taught to take on Celts wielding long broadswords this way – but as a soldier I had been armoured, with weapons of my own, not to mention ranks of snarling colleagues forming impenetrable blocks on either side.

I stepped towards him. Light flashed; he whirled the axe again. I leapt like a Cretan dancer, heels to buttocks, saving my legs. Grabbing at a branch, I landed safe then put a tree between us. I managed to crack off the branch partially, but a long green strand of bark peeled back and caught fast. Useless.

Dear gods, this was a town boy's nightmare: I wanted to be walking decent pavements where the criminals followed proper rules of misconduct and where I could drop into a winebar when the pace grew hot. Here I was, facing a desperate axeman in a misty wood, starved, exhausted, deserted by, my only helpers, and now risking amputation of my lower limbs. As a way of earning a salary it stank.

I dragged at the branch and this time it broke free. The stem was thick enough to make the axe bite if he hit it. Better still, the far end divided into a mass of twiggy branches, which were still in leaf. As Thurius made his next swing, I dodged the glinting blade: Then I jumped at him, thrusting the great bunch of long twigs full in his face. He started back, stumbled, lost ground. I pressed on, dashing my branch again at, his eyes. He turned and ran. I followed but the branch caught in the undergrowth and I lost hold of it. I let it go and kept running.

Thurius was pounding hard, still towards the track. I veered off to one side, putting myself between him and escape from the estate. Smashing down bushes, we struggled on. A fox broke cover suddenly and scampered away. A jay lumbered off with its strange laboured flight and a harsh cry. Once again I fancied – I heard hoofbeats, this time much closer. Breathing hurt. Sweat was pouring off me. My aching legs could hardly keep going. Even so, as Thurius reached the track I was gaining; then, my foot skidded on a clump of fungi and dropped into a hole, making me pull up with a cry of anguish. I managed to stay upright, but my boot turned over under me. I hopped free of the squashed and slimy toadstool stems, slipped again, then stepped wincingly after Thurius. He stopped and glanced back, then set off down the track.

Ignoring the pain; in my ankle I began to hop with what had to be one final sprint. A twisted ankle rights itself,

I though it prefers time to settle. I had no time. My strength would give out at any moment. But I would catch him first if I could.

I heard a horse whinny. My heart sank, imagining he had a tethered mount somewhere. Then Thurius threw out his arms. Horse and rider had crashed out of the wood on the far side, and were galloping straight at him,

He couldn't stop. He stumbled and lost the axe. The horse reared over him, but was reined back. Thurius staggered, still, keeping upright, still determined to escape. He feinted with one arm at the horse, ducked its hooves, and hurled himself down the track again. I had kept running. I crashed past the horse, glimpsing a familiar rider, who dragged it sideways to give me space. Then I caught up and launched myself on to Thurius.

I flung him down, face first in the leafmould. I was so angry that once I made contact he stood no chance. I fell on his back, making sure I landed heavily. I pinioned his arms and clung on, commanding him to give up. He wrenched sideways, still thrashing. I pulled him up bodily and smashed him face down again. By then the horseman had dismounted and come rushing up., Next minute, my furious helper was booting Thurius in the ribs as if he meant to finish him.

`Steady!' I yelled, leaning out of the way of the flying boots. It stopped both of them. Thurius finally capsized with his face in the ruts of the track.

Still astride my captive, I started controlling my breathing. `Nice action,' I gasped, looking up at the other man.