"So… you know FrontinusF He seemed fascinated by my famous contact.

"We worked together once," I said gently. "He was the consular, enthroned; I was the runabout at gutter level." It was not quite true, but passed off the connection graciously.

"Even so working with Frontinus!"

"Maybe people will be saying to you one day "working with Falco!", Rectus."

Rectus considered that; saw it was ludicrous; stopped being in awe of my prestigious friends. He then told me sensibly about his discipline.

Scale was his main challenge. He had to cope with enormously long pipe runs, both to bring fresh water in along the various wings, and take away the rain outfall, which would be of huge volume in bad weather. Where his water pipes and drainpipes had to pass under buildings, it was essential to ensure they were completely free of leaks, their joints stopped tightly and the whole length surrounded by clay, before they became inaccessible under the finished rooms. Domestic needs were only part of his brief. Half the paths in the garden area would be laid over pipes to supply fountains. Even the wild garden by the sea, so richly supplied with streams and ponds, still needed a delivery pipe at one point for watering plants.

He was a real expert. When we were talking about how he planned to drain the garden, he told me that on one run the drop would be barely one in one eighty-three. That's a virtually invisible slope. Measuring it accurately would take patience and brilliance. The way he talked convinced me Rectus possessed that skill. I could envisage that when everything was up, water would be gushing away down this near-horizontal conduit quite satisfactorily.

Pomponius had finished wrangling with Magnus. We saw Magnus stumping off with Cyprianus, both shaking their heads. Now the architect came wafting over to us, clearly intending to have a go at Rectus. The high-flown bully was transparent. He had failed to impose his will on the experienced surveyor and clerk of works, so he was now planning to shower scorn on the drainage scheme.

Rectus had dealt with Pomponius before. He rose from his block of limestone looking nervous, but he had his speech ready: "I don't want a fight, but what about my farting tank? Look, I'm telling you now, in front of Falco as my witness, the tank needs to be programmed in this week."

I was remaining neutral. I stayed seated. But I was there. Maybe that was why Pomponius suddenly backed off. "Cyprianus can write out a docket and I'll sign it. Fix it up with him!" he ordered curtly. As clerk of works, Cyprianus was in charge of allocating labour to the task; he also had the authority to call up the right materials. Apparently that was all Rectus needed. He was a happy man. Pointless tension evaporated.

Elsewhere things were not so calm. In the daytime the site was always noisy, even when little seemed to be happening. Now, shouts that sounded far more urgent than normal rang across the open area. I jumped up and stared over, towards the south wing. It looked as if a fight had started.

I set off there, running.

XXII

men had flocked to the scrimmage. More labourers than I had been aware of that day on site popped out of trenches and rushed to watch, all yelling, in various languages. I was soon in a crowd, jostled on all sides.

I pushed to the front. Jupiter! One of the protagonists was the elder Philocles, the white-haired mosaicist. He was going at it like a professional boxer. As I burst through the crowd, he knocked the other to the ground. Judging by his paint-spattered tunic, the man who fell had to be a fresco artist. Philocles wasted no time in exploiting his advantage. Astonishingly, he leapt up in the air, drew his knees up, then crashed down on his opponent, full in the stomach, landing with both boots and all his weight. I sucked in air, imagining the pain. Then I fell on Philocles from behind.

I thought others would help drag him off. No luck. My intervention was just a new phase in the excitement. I found myself tussling with this red-faced, white-haired, violent old-timer who seemed to have no sense of danger and no discernment over whom he attacked but only a furious temper and wild fists. I could hardly believe it was the tight-mouthed man I had met that morning.

As I tried to prevent Philocles causing more damage, to me especially, Cyprianus turned up. When the stricken painter struggled to his feet somehow and for no reason threatened to join in fighting me, Cyprianus gripped his arms and pulled him backwards.

We held the mosaicist and painter apart. They were both madly struggling. "Stop it! Cut it out, both of you!"

Philocles had gone crazy. No longer the taciturn drone who held himself aloof, he was still thrashing like a beached shark. He swung madly. Caught out by mud underfoot yet again, I skidded. This time I managed to stop falling, at the expense of another jarring of my back. Philocles lurched the other way, hanging like a deadweight so he pulled me over. We rolled on the ground, with me grinding my teeth but clinging onto him. Being younger and tougher, eventually I hauled him back upright.

He broke free. He swung around and took a swipe at me. I ducked once, then I clipped him hard around the head. That stopped him.

By now, the other man had realised just how painful being jumped on felt. He doubled up, collapsing to the ground again. Cyprianus bent over, holding him. "Get a plank!" he yelled. The painter was barely conscious. Philocles stood back, clearly reconsidering. Suddenly he was worried. His breath came fast.

"Is that Blandus?" I asked Cyprianus. The man was being stretchered onto a board so people could carry him. Alexas, the medical orderly, squeezed through the press to examine him.

"It's Blandus," Cyprianus confirmed grimly. He must be used to settling disputes, but he was angry. "Philocles, I've had just about enough of you two and your stupid feuds! You're going in my lockup this time."

"He started it."

"He's out of it now!"

Pomponius arrived. All we needed. "Oh this is ridiculous." He rounded on Philocles, shaking his finger furiously. "For the gods' sake! I have to have that man. There's nobody to touch him within a thousand miles. Will he live?" he demanded of Alexas, as peremptory as could be.

Alexas looked worried but said he thought Blandus would live.

"Put him in your sickbay," ordered Cyprianus roughly. "Keep him there until I say otherwise."

"Tie him to the bed if you have to! I look to you, Cyprianus," declared Pomponius in a mincingly superior tone, 'to keep your workforce under some control!"

He stormed off. Cyprianus glowered as he watched him leave, but somehow refrained from all the optional rude sounds and gestures. He was a standard clerk of works: first class.

The crowd melted away fast. Managers tend to have that effect. Blandus was carted off, with Alexas running alongside. Philocles was manhandled away too. Among the mutters as the melee dispersed, I heard one provocative jeer in particular. It was aimed at Lupus, the foreign-labour supervisor, by a sinister, bare-armed tough nut who was covered in woad patterns.

"Don't tell me," I muttered to Cyprianus. "That's the other gang leader the local workers' chief I see he has a feud with Lupus?" They had gone off in opposite directions, or it looked as though another tight would have occurred. "What's he called- Mandumerus?" Cyprianus said nothing. I took it I was correct. "All right so what's with Philocles and Blandus?"

"They hate each other."

"Well, so I see. I'm not reduced to reading with a concave spyglass yet. Tell me why?"

"Who knows?" replied the clerk of works, quite exasperated. "Jealousy, say. They are both leaders in their field. They both think the palace scheme will collapse without them."