So we all trooped back through Pompeii and out to the port. The plumber plodded along in silence, like a man who has learned to be polite to lunatics through dealing with civil engineers.

Thinking about my nephew, I had forgotten to check my ship's arrival, but when the Emperor says a vessel will be moved from Ostia to the Sarnus you can reckon that the sailors will set off immediately and not stop to dice for any sea nymphs on the way.

The ship called the Circe was waiting in the harbour. This was one of the Tarentum galleys built for Atius Pertinax-a huge, square-sailed merchantman, thirty foot deep in the hold, with two great steering paddles either side of a high stern which curled up and over like the slim neck of a goose. She was sturdy enough to have braved the Indian Ocean and float back with sweet cargoes of ivory, peppercorns, gum tragacanth, rock crystal and luminous sea pearls. But since her maiden voyage she had led a harder life; Pertinax had been using her last year to thrash round Gaul. Now she was laden to the gunwales with a cold Atlantic shipment-long, four-sided ingots of British lead.

Ventriculus whistled admiringly when we all piled on board.

'I told you what they were,' I said as he inspected the ingots in amazement.

'I do hope,' he queried bluntly, 'these are not lost Treasury stock?'

'Just separated out from the system,' I replied.

'Stolen?'

'Not by me.'

'What's their history?'

'They were part of a fraud I investigated. You know how it is. They might have been useful for evidence so they were parked in a yard while the higher-ups all wondered whether they wanted a court case or a cover up.'

'What's the decision?'

'Nothing; interest faded out. So I found them still lying around… There's no documentation attached to them, and the Treasurer at the Temple of Saturn will never spot the loss.' Well; probably not.

'Any silver still in these?' Venticulus asked, and he looked disappointed when I shook my head.

Petronius was gazing into the open hold with the grey face of a man who bitterly remembered being posted to a frontline fort in a province at the end of the world: Britain, where whichever way you turned, somehow the filthy weather always met you in the face… I saw him square his shoulders, as if they still felt damp. He hated Britain almost as much as I did. Though not quite. He still reminisced about the famous east coast oysters, and his eye sharpened keenly after women with red-gold hair.

'Does Vespasian know you've palmed this stuff?' he muttered in an anxious tone. He had a responsible job with a respectable salary; his wife liked the salary almost as much as Petronius loved his job.

'Special franchise!' I assured him cheerfully. 'Vespasian enjoys making a quick denarius on the side.'

'Did you ask him to chip in with you?'

'He never said no.'

'Or yes either! Falco, I despair of you-'

'Petro, stop worrying!'

'You've even pinched the ship!'

'The ship,' I stated firmly, 'is due to be returned to the indulgent millionaire who bought it for his son; when I've finished I'll inform the old duffer where his nautical real estate is berthed. Look, there's a fair weight to be shifted here; we had better get on… Oh, Parnassus! Where's that lad?'

With a sudden pang of fright I sprang out on deck, scanning the harbour for Larius, who had disappeared. Just then the half-baked lunatic came roaming along the quayside with his characteristic lope and a vacant expression, gawping at the other ships. I caught sight of him-not far from a wrinkly stevedore with what looked like ninety years of sunburn lacquering his features, who was sitting on a bollard watching us.

We had a hard day of it.

We spent the morning unloading ingots into our ox cart. Ventriculus rented a workshop in the Theatre quarter; the Stabian Gate was nearest but so steep that instead we trundled along to the Nuceria Road Necropolis, chipped off the corners of a few marble tombs, and turned into town there. Our ox, whom we called Nero, soon looked sick. He had a charitable nature but evidently thought hauling great baulks of lead went beyond the call of duty for a beast on holiday.

Ventriculus started work at once. I wanted him to turn the ingots into water pipes. This meant they had to be melted down, then rolled out into narrow strips about ten feet long. The sheet lead was cooled, then curved around wooden battens until the two edges could be pinched together and soldered with more melted lead. (Making this seam is what gives pipes their pear-shaped section if you look at them end on.) Ventriculus was willing to provide various widths, but we concentrated on a regular-sized bore: quinariae, about a digit and a quarter in diameter-the handy household size. Water pipes are unwieldy objects: even a ten-foot quinaria weighs sixty Roman pounds. I had to keep warning Larius, who was short on concentration, that he would know all about it if he dropped one on his foot.

As soon as we had transferred all the ingots to the workshop and the plumber had produced a batch of pipes, we sent the cart back to Oplontis; Ventriculus threw in gratis a sack of bronze taps and stopcocks, which shows what kind of profit he was making on the deal. The plan was that I should take round samples and make on-the-spot sales, but wherever possible I would fix up major contracts for Ventriculus to carry out at a later date. I wanted to take a large instalment back to Oplontis now, which meant only one driver and no passengers; Petronius would drive the load. He was big enough to protect himself, and got on well with Nero. Besides, although he had never complained I knew Petro wanted to speed back early, to placate his wife. I felt a real public benefactor when I sent him off.

I treated the plumber and Larius to a splash in the Stabian baths. Then before our hike home the lad and I trooped off via the harbour so I could have a last word with the captain of the Circe. I showed him the notebook I had brought home from Croton, and told him my theory that the list of names and dates referred to ships.

'Could be, Falco. I know Parthenope and Venus of Paphos as Ostia corn transports…'

While we were talking I lost sight of my nephew yet again.

I had left him mooning on the quayside. Scratched graffiti of two gladiators gave witness to where he had been amusing himself last: instead of the pimply kneed rabbits we had seen adorning tavern walls in town, my scallywag's doodles had powerful lines; he could really draw. But artistic talent is no guarantee of sense. Keeping track of Larius was like house-training a chameleon. Ships exerted a special fascination; soon I was dreading that he had slipped aboard one as a stowaway…

Suddenly he sauntered back in sight: gossiping with the well-tanned crow's-nest type I saw spying on us with such interest earlier.

'Larius! You flea-brained young punk, where in Hades have you been?' He opened his mouth casually to answer, but I cut him short. 'Stop dodging off, will you? It's bad enough looking over one shoulder for some manic assassin, without constantly scouring the horizon for you!'

Perhaps he intended to apologize, but my fright had made me so annoyed I just nodded to the curious stevedore then dragged my nephew away by one ear. Remembering Barnabas brought another cold sweat under my tunic. Snatching a final glance around the port as if I feared the freedman might be watching us, I stormed off in the direction of the hole we were calling home.