`Right, Falco,' said Bolanus. I don't think he ever intends that they should-turn up in the water supply in Rome. But sometimes smaller and lighter parts- hands, for instance – find their way into the Novus basin, and then on into the-channel. The killer may still be unaware that this happens. If they happen to float out of the filtration system, the body parts will travel on to Rome. At the end of the run, two aqueducts join on, one arcade; the Novus is carried above the Aqua Claudia, with switching shafts. And the Claudia also has an interchange with the Marcia, as I showed you both,-'

Frontinus and I nodded, remembering how we saw' the torrent crashing from one aqueduct to the other.

`So we can see how these small relics might move around once they reach Rome. The only puzzle,' said Bolanus slowly, `is the first hand, the one that Falco found, which was supposed to have been pulled out on the Aventine, in a castellum of the Aqua Appia.'

It seemed a long time ago that Petro and I had shared a drink in Tailors' Lane. `Are there no links between the Aqua Appia and any of the Tibur channels?' I asked.

`There are possibilities. The Appia source isn't underground; it starts at a reservoir in some ancient quarries on the Via Collatina.'

`So anyone could have driven past one day and thrown in a package?'

Bolanus didn't like it. `More likely your public fountain has two jets, drawn from different aqueducts. It enables us to maintain a supply by a swap if needs be. It's true the Appia serves the Aventine; the terminus is by the Temple of Luna. But there could be a second feed from the Aqua Claudia '

`So it all fits,' Frontinus interrupted. `And it all starts here.’

`But who is this bastard?' fretted Bolanus, for whom the hunt was starting to be personal.

`All I found back along the road,' I reported, `was a trio of cheerful brothers who – apparently – have not been to Rome for ages, with a few slaves, plus an old man who looks too feeble to go anywhere.'

`So what do you suggest?' asked the Consul `We know what the bastard does, and we know he does some of it here. Unless we act, at the next festival he will be here doing it

again.''

'If we were very cold-blooded,' I answered him slowly, `when the Augustan Games start they were only a week away – we would station your public slaves behind trees all the way up this valley from here to Sublaqueum, telling them to make themselves look like twigs until they spot someone chucking something suspicious out into the Anio:

`But to do that and catch him in the act – '

`- a woman has to die first.'

Frontinus took a deep breath., `We shall do it if we have to.’ Pragmatic to the end, it seemed.

I smiled. `But if we can, I want to catch him earlier.' `Good, Falco!'

`We have a few leads. Before the Augustales begin, I want us to be set up for trapping: him in Rome. We haven't much time. I'll stay, at Tibur for one more day, and give our suspects list a final look-over. I want to be quite sure we haven't missed anything. We know the killer is prepared to travel long distances. Maybe he actually lives at Tibur but, comes, up into the hills when he starts butchering the bodies.'

So it was back to Tibur. As we moved away from the sunny riverbank a startled kingfisher swooped away in a brilliant flash of colour. Behind us a dragonfly hovered in stunning livery above the sparkling and seemingly clear waters of the contaminated Anio.

FIFTY ONE

For discovering our festival-visitor, Tibur itself still seemed the best base. Back along the Via Valeria we saw little to interest us. There were one or two grand country homes, their porticos bearing the names of famous men, although most lay deserted and some of the names were so illustrious that even the high-ranking Frontinus blenched at, the thought of politely suggesting that the current generation might be involved in a long and extremely sordid series of murders. In between, the farm-owners geared their trips to Rome to markets rather than festivals. The absentee land lords, of whom there were plenty, ruled themselves out by their very absence as they do from most responsibilities.

Back in Tibur my own reception was mixed. Julia Junilla was crying when I arrived at the nettle patch farm. `Dear, dear – come to Father!' As I picked her up, mere tears turned

to lusty, red-in-the-face screams.;-

`She is wondering who this stranger is,' Helena suggested, mildly, above the row.

I could take a hint. `And what are you thinking, my darling?'

`Oh I remember all too well.'

The baby must have remembered too, because she suddenly welcomed me with a very squelchy burp.

Lucius Petronius, my beaten-up partner, was looking better. His bruises were fading. By lamplight he just looked as if he hadn't washed his face for a week. He could now move about more freely too, when he bothered to exert himself. 'So how was seeking, suspects in Sublaqueum?

`Oh, just how I like it – all gazing at idyllic scenery and thinking poetic thoughts.'

`Find anything?'

`Charming people who never go anywhere. Clean-living country types who lead blameless lives and who tell me oh, no, they entertain no suspicions that any of their pleasant neighbours may be cutting up: female flesh in some grim little hut in the woods.'

He stretched his big frame. I could tell that our convalescent boy was started to feel bored. `So what now?'

`Back to Rome, fairly urgently. But I'm quickly going to double-check some of the fancy villas Julius Frontinus went to earlier.'

`I thought you sent him to the ones that would refuse you access?'

`I'm going disguised as an itinerant handyman – the type I know every one of them will welcome with open arms.'

He raised an eyebrow sceptically. `Does that type exist?'

`Every fine home in the Empire has at least one fountain that won't work. I shall offer to fix it for them -' I grinned at him. `And you can come along as my terrible apprentice if you want.' Petronius accepted readily, though he did try to convince me his natural position was as the fountain fixer's manager instead. I said since he looked like a roughneck fresh from a tavern fight he had to play the tool-carrying role. `Next door's kitchen maid not up to much then?'

`Too young,' he smirked. `Too bloody dangerous. Besides,' he admitted, `she smells of garlic and she's dafter than a painter's brush.'

Every investigation should include an interlude where the trusty informer puts on a dirty one-sleeved tunic, slicks his hair back with salad oil, and sets off to knock on doors. I had done it before. Petronius, used to imposing his requests for information by means of a cudgel and a threat of imprisonment, had to learn a few tricks – mainly how to keep -quiet. Still, his Auntie Sedina assured him he was perfect at looking gormless (the first requirement in a tradesman). Helena put us through a rehearsal, at which she made various sound suggestions, such as `Pick your nose with more conviction!' and `Don't forget to suck your teeth' and murmur, "Ooh! This looks like a tricky one; I think you've got a problem here… "'

The way it worked was this: dressed in scruffy togs and carrying a large bag which contained various heavy chunks of equipment we had collected from the farm outbuildings,

Petro and I sauntered past the elegant gates of the opulent homesteads we wanted to investigate. We were always eating a melon. As the fierce guards came out to glare at us walking by, we greeted them cheerfully and offered them a slice of fruit. After passing the time of day for a few moments we usually persuaded our new friends, with melon juice still running down their chins, to let us in. We heaved our bag up the drive, and very respectfully informed the suspicious house steward that this was his big chance to surprise the owner by renovating the fountain that had failed to work for years. Most let us try, since they had nothing to lose. While we applied our ingenuity they naturally stayed there watching, just in case we were burglars after the drinking cups. That gave us the chance to engage them in chat, and once we had the fountain flowing again (which we usually achieved, I'm proud to say)' they were so grateful they were ready to tell us anything.,