"Is it still there?"

"No. Drove away later."

"Heading where?"

"Umm…" He tried to remember. "Can't be sure."

"Oh that's helpful! Keep looking. This could be part of some materials racket. Any time you are on your own near the parked-up wagons try inspecting them surreptitiously, will you."

He scowled. "I was hoping I could finish skulking."

Tough!" I said.

Not long after that, Favonia was sick on my shoulder- a good excuse to break up the party and retire for the night.

"Oh it will sponge off! "jeered Maia as we went to our rooms. I was too experienced to be fooled. I had run out of tunics too.

The workmen who had been out to the canabae started coming home just as I nearly fell asleep. They rambled back in dribs and drabs, mostly quite unaware they might be disturbing people. They probably thought they were really quiet. Some were happy, some obscene, some full of loud animosity for the group in front. At least one found that he needed an extremely long pee, right against the palace wall.

Way into the hours of darkness, their noise finally ceased. That was when little Favonia decided to wake up and cry non-stop until morning.

XXV

M'LSi'M served on a building site is disgusting. Unpalatable eve rages must be provided to labourers deliberately, to discourage them from taking time off for drinks. To troops, stuck at the back end of nowhere, marching a long road through a dense forest or trapped in some windswept frontier fort, even sour wine seems welcome whilst in an emperor's Triumph, when the army returns home to Rome in splendour, they are awarded real mulsum. That's four measures of fine wine mixed with one of pure Attic honey. The further you go to the outposts of the Empire, the less hope there is of an elegant wine or genuine Greek sweetener. As nourishment deteriorates, your spirits droop. By the time you reach Britain, life can get no worse. Not, that is, until you are sitting on a building site and the mulsum boy arrives.

Refreshed by my night's rest (that's another bitter quip), I had crawled to my office. Bleary-eyed, I set to, peering at some wages bills in case I could find Gloccus or Cotta listed. I had been first up in our household. There was no breakfast. So I fell on my beaker cheerfully once the sniffing boy arrived. A mistake I would only make once.

"What's your name, boy?"

"Iggidunus."

"Do me a favour-just bring me some hot water next time."

"What's wrong with the mulsum?"

"Oh… nothing!"

"What's wrong with you, then?"

"Toothache."

"Want do you want water for?"

"Medicine." Cloves are supposed to dull the pain. They did not work on my dying molar; Helena had tried me on cloves for the last week. But anything would taste better than the mulsum boy's offering.

"You're an odd one!" Iggidunus scoffed, bumming off in a huff.

I called him back. My brain must be working in its sleep. I had not found Gloccus and Cotta, but I had spotted an anomaly.

I asked whether Iggidunus served a brew to everyone, the entire site. Yes he did. How many beakers? He had no idea.

I told Gaius to provide Iggidunus with a waxed tablet and a stylus. Of course he could not write. Instead, I showed the boy how to create a record using rive-barred gates. "Four upright sticks, then one across. Got it? Then start another set. When you finish, I can count them."

"Is this some clever Egyptian abacus trick, Falco?" Gaius grinned.

"Do one round of the site, Iggidunus."

"I only do one. It takes all day."

"That's hard on the people who miss you."

"Their mates tell me. I leave their cup with a tile on top."

"So there's no escape! Count every mulsum cup you serve. Also, put down a stick for anyone who should get a beaker but who says no thanks. Then bring the tablet back to me here."

"With some hot water?"

"That's right. Boiling would be nice."

"You are joking, Falco!"

Off Iggidunus went. I placed my beaker of mulsum on the floor for Nux. My shaggy hound took one sniff, then stalked off to the clerk's side of the office.

He stared at me. "Gaius, can you find me the tallies for the caterer's regular food order?"

He shuffled around, identified them, heaved them over to me. Then he leaned across, so he saw which records I was already working on and the notes I had scribbled. It took him no time to make the connection. "Oh rats!" he said. "I never thought of that."

"You see my point." I was cradling my cheek gloomily. "Nothing matches, Gaius. The wages bill is high. Money drains away through a sieve and yet look at these food invoices. The quantities of wine and provisions brought in don't marry up for those numbers of men… I'd say the supplies quantities are about right for those I've seen on site. It's the labour figures that are suspect. If you look around outside, we have hardly any of the trades, other than basic heavies who can dig trenches."

"The workforce is low, Falco; that's proved by the way that the programme keeps slipping. The clerk who keeps the programme doesn't care, he just plays dice all day. The project team explained it as "delays due to bad weather" when I queried it."

"They always say that." Trying to employ Gloccus and Cotta back in Rome had taught me the system. "Either rain threatens to spoil their concrete or it's too hot for the men to work."

"None of my business anyway; I'm here to count beans."

I sighed. He had tried. He was just a clerk. He had so little authority everyone ran rings round him.

"It's time you and I counted heads, not beans." I took him into my confidence. "Here's my theory: it looks like at least one of our merry supervisors is claiming for a phantom labour force."

Gaius leaned back with his arms folded. "Whew! I like working with you, Falco. This is fun!"

"No, it's not. It's very serious." I could see a black hole opening up. "It may explain why Lupus and Mandumerus are at odds. There could be a turf war for control of the labour fiddle. That's bad news. Whichever of the supervisors is running the racket, Gaius, listen: take great care. Once they know we've found out, life will become extremely dangerous."

Gaius then continued with his own work rather quietly.

I slipped out later, to look into another aspect. I had been thinking about Magnus and his peculiar behaviour yesterday around the delivery carts. He had claimed he was 'checking a marble consignment'. I thought it unlikely but clever frauds often deceive you not with lies but with cunning half-truths.

I wanted to find the area where marble was being worked. I was led there by the screeching and scraping noises of saw-blades. With Nux at my heels, I made my way into the fenced enclosure. Men were preparing and squaring up newly delivered irregular blocks, using hammers and various grades of chisels. Nux ran off with her tail down, alarmed by the din, but I could only put my fingers in my ears as I hung around, inspecting various upright slabs.

Four men were pushing and pulling a multi-bladed saw to split a blue-grey block into pieces for inlay. The un toothed iron blades were supported in a wooden box frame, its progress lubricated by pouring water and sand into the cuts. By a slow and careful process, the men were slicing through the stone to produce several delicately fine sheets at once. From time to time they lifted the saw, resting their hands. A boy then moved in to brush away the damp powder produced by their labour, the marble 'flour', which I knew would be collected and used by the plasterers, mixed into their topcoats to give an extra fine glossy finish. The boy then fed new sand and water into the saw grooves to provide abrasion, and the sawyers resumed their cutting.

The resulting slabs would then be stacked vertically according to