"What killed him?" he asked. "And when?"

Di Capua sighed.

"You've worked here a million years, Peroni. You know what a man looks like when he's been beaten up. When did it happen? I apologize. The battery died on my crystal ball. Come back later when I've got a new one."

"Some big tough guy who liked to use his fists," the cop said. He pointed at the corpse of Spallone. "The other guy's got a messy head too."

Di Capua folded his arms.

"Not unusual with river deaths. Could have hit the stonework falling in. Got washed around by the swell. When we've done the autopsy then I'll tell you."

Peroni leaned over the dead psychiatrist and said, "Nah. If you hit stonework you get grazed. The Roma kid could have gone that way. He's cut. Spallone here ..." He looked more closely. A bell was ringing but too faintly. "He's bruised. Swollen. No blood."

"Blunt force trauma," Di Capua said.

"That tells me a lot."

The pathologist folded his arms and looked a little cross.

"Why should I tell you anything? You're not dealing with either of these guys. Not as far as I know. Inspector Vieri's been round seeing Spallone's widow. He sent some wet-behind-the-ear agente to wake up the little hood's camp at seven. No one talking, of course. If it wasn't for the prints and photos we couldn't even ID him. Agente said even his own father wouldn't help. Chances are it's a gang rivalry thing and some other Romanian hood will wind up dead a couple of days down the line ..."

"Dead quack gets an inspector and the full team. Dead immigrant gets a visit from an infant. The Roma mourn their dead, Silvio. Just like we do. Also you're forgetting the deal."

"The deal?"

"You don't do cop work and we don't dissect your corpses."

Di Capua was starting to get mad.

"Yeah, well ... One drowned doctor. One beat-up street kid. And you hanging round here as if you care. Don't you have work to do?"

"There's always work if you look for it," Peroni answered. "Right now I'm ..." He searched for the right word. "Foraging."

"Then why don't you go forage somewhere else?"

"What next?" the big man answered, ignoring him again. "Slice and dice. Weigh the organs. Check the spleen and things. Peek inside at every last little bit of them, working or not, until you get something to write down on your report ... what? Tomorrow? The day after?"

Di Capua opened his arms wide.

"That's the way it goes. Custom and practice. One mistake and we all could hang. As you know. Now ..."

"Just a favour," Peroni said quickly, coming close, putting a huge arm round the skinny, balding pathologist.

"Why should I ...?"

"The socks," Peroni interrupted. "Those ..." He pointed at the two sets of feet in front of them. Shoes off already. Ankles splayed. Very dead.

"What about them?" he asked.

Peroni laughed, took away his arms, clapped his big pale hands. Then he retrieved a pair of scissors from the kidney bowl on the silver autopsy table and carefully cut up through the front of all four trouser legs. Spallone's expensive dark blue barathea didn't give in easily. The Roma kid's garish polyester was so flimsy he could slice it apart just by lifting the lower blade.

"Are you kidding me?" he asked when he finished.

Both men were wearing long socks pulled up close to the knee. Odd socks. The one on each right leg light-blue and unpatterned. The other pale-grey and ribbed so subtly the markings were scarcely noticeable.

The fabric of the blue socks seemed as cheap and thin and as artificial as the kid's shiny jacket and trousers. The toes were close to going on both. The grey ones were newer, wool maybe. Expensive.

"I never knew a young guy who wore long socks like that," Peroni murmured. "Curious ..."

"Gianni ..."

"But not as strange as the fact two dead men, found the same morning in different parts of Rome, seem to have dipped into the same sock drawer before they went out for the night."

"You don't know that!" Di Capua protested.

Peroni retrieved his phone from his pocket and took a picture of the dead legs. Then he reached forward and very lightly tweaked Spallone's dead big toe.

Di Capua shrieked.

"That was the favour," the big man added. "I don't leave till I get it."

The pathologist grumbled. But he still went and got a pair of tweezers and, very carefully, pulled each sock from each dead limb, depositing them in four separate plastic envelopes.

Then the two men peered at the plastic bags. One set, the grey ones, had a brand, a pricey one from Milan. The others looked the kind people picked up three pairs to the euro from a street stall. No name. Nothing to identify them.

"I can check on the fabric to see if they're the same too," Di Capua said, serious now. "Give me till the end of the afternoon."

"Thanks," Peroni said, and slapped the pathologist hard on his white-jacketed shoulder. "That would be good."

2.

Inspector Vieri's team worked on the floor below, in an office next to Falcone's unit. Peroni's customary home was empty now. Costa had taken everyone except him to Fiumicino for the drill there. Peroni knew why he'd been left behind. He always found it difficult to keep a straight face when the management decided to lead everyone in the merry dance known as role play.

Vieri had arrived the previous month sporting the finely tailored suit and standoffish manners of a young officer eyeing some rapid progress up the ranks. He had all the traits that mattered when it came to catching the eye of promotion boards: a couple of degrees from fancy universities, a spell at business school, periods in some of the more fashionable specialist units involving terrorism, organized crime and financial misdemeanours. The man was all of thirty-three and had never, Peroni suspected, punched or been punched once in his entire life. To make matters worse he hailed from Milan and spoke in a gruff, cold northern voice that matched his angular pasty face. He never set foot in the Questura without shoes so polished they looked like mirrors. No one ever saw a hair out of place on his bouffant, gleaming black-haired head. The general opinion in the Questura bar round the corner was he'd make commissario before he turned forty, maybe even thirty-five. After that the direction of his golden future was anyone's guess. Just to rub salt in the wound the man's wife was a beautiful redhead who worked as a producer for the state TV company RAI. All things considered, as far as the average grizzled Roman cop was concerned Vieri might as well have worn a sign saying "Shoot me" on his back.

This morning's suit was dark-blue barathea, not unlike the shrunken jacket and trousers clinging to the corpse of Spallone upstairs. Peroni, who had barely met the man, strode over smiling, introduced himself and asked if he could help.

Vieri gave him a taciturn stare. He'd brought a handful of officers from Milan with him when he arrived in Rome, turned them into his personal confidantes, people he spoke to before any of the locals whenever possible. An unwise decision for such a clever man.

"Don't you have work in your own unit?" Vieri asked. He didn't look in the least grateful for the offer of free manpower. Just suspicious.

"Sure," Peroni replied pleasantly. "But sometimes a little local knowledge can help an officer who's new around here. I hope you don't mind my saying. Rome's a village really, sir. The peasants tend to stick with their own and ..."

Vieri wasn't listening. He was staring at his phone, a model that was decidedly fancier than anything handed out as stock issue to the average Questura officer. Another innovation from Milan.

"The socks," Peroni added.

The young inspector scowled and waved him down. He was reading his email. It seemed to Peroni he was the kind of man who thought every message, whatever its contents, was of overriding importance, if only because it was addressed to him.

Vieri barked out a couple of orders to two men across the room. Local guys. Peroni knew them both. One of them nodded. The other briefly stared at Peroni with hooded eyes.

"The socks," Peroni repeated. "If you'd care to come upstairs to the morgue I can show you. Better to see than try to explain sometimes." He scratched his ear. "I keep trying to work out how many possible solutions there might ..."

"I don't approve of police officers interfering with the work of the forensic department," Vieri said rather pompously, not once taking his eyes off the phone.

Peroni felt his hackles rising and wondered whether he cared if this man noticed or not.

"It's cooperation, not interference, sir ..." he began.

To Peroni's surprise Vieri's hard stare managed to silence him.

"I know it was once fashionable for police officers to watch and sigh and groan as pathologists go about their business," the inspector declared. "Truthfully it's a waste of time. Theirs and ours. When forensic have something useful to tell us, they will do so and I will listen. In the meantime ..."

Peroni watched him bark out yet more orders. Hunts for CCTV images. Mobile phone records. Car details. A call to the media to see if anyone had seen a man answering Spallone's description near the river the previous night. Nothing about the Roma kid.

"You don't think it was suicide?" he asked when Vieri was finished.

"I don't know, agente," the man replied curtly. "I have no preconceptions. His widow a.s.sures us he was a troubled man. He absented himself from home at regular intervals." Vieri shrugged. "I have no reason to disbelieve her. Spallone was a widely respected man. He sat on the board of several public bodies. He was a patron of the opera. Known in political circles. We will investigate and report in due course." For the briefest of moments his stony, ascetic face displayed something approaching doubt. "I imagine she's right. They were a wealthy couple, well-connected. Hard to see anything else."

Peroni stood there, wondering whether to point out that Vieri had contradicted himself already. Instead he said, "I would really appreciate two minutes of your time to see these socks."

"You didn't listen to a word I said, did you?" Vieri snapped.

"On the contrary. I hung on every one."

The young inspector turned away from him. He was listening to someone else speaking on the phone.

"The Roma kid ..." Peroni began, not moving a centimetre, speaking a little more loudly to regain Vieri's attention.

"If the father can't even stir himself to come and identify the body there's very little I intend to do at the moment. They can stew until they want to talk, or sort it out between themselves and then we'll pick up the pieces."

Peroni blinked, struggling to believe what he was hearing, though, with a moment's reflection, he knew the man's callous words should not have come as such a shock. This was the modern force, not the one he'd joined thirty years before. Priorities, procedures, resource management ... and the keeping sweet of bereaved relatives of men who sat on public boards and patronized the opera. All these mean, inhuman practices had come to swamp the previous shambling chaos through which officers sifted hopefully, trying to sort good from bad, the crucial from the inconsequential, with little to help them other than their own innate intelligence and knowledge of their fellow men and women.

"You'll never get a thing out of the Roma if you send kids to talk to them," he said with undisguised brusqueness. "It doesn't work like that."

Vieri's eyebrows which were, the old cop now noticed, manicured and shaped rose as if in a challenge.

"You think you could do better?" the man from Milan asked.

"I know it," Peroni replied straight away. "You want me to go there?"

"You don't work for me," Vieri said, looking him up and down. "Frankly I prefer younger officers. My problem, not yours ..."

With that he turned and started talking to his men again. About phone records and databases, video and intelligence. Peroni guessed this team could try to work two cases no, one and a quarter at best for the rest of the day and never set foot outside the building, never do a thing without having a phone to their ear, their fingers on a keyboard, their minds tuned for a call from the morgue and the delivery report that said: it's fine, go home, there's nothing you can do.

One of the men Vieri had brought with him from Milan was watching Peroni with a look that spoke volumes. It said: get out of here.

"You know," Peroni said, touching the guy's arm and nodding at the sunny day beyond the window, "it's really not scary out there. You won't even get sunburn, I promise. You should try it some time."

Then he marched out of the room, along the corridor, back into his own empty office, looked at the vacant chairs there, the silent phones, the desks, the computers, papers strewn everywhere.

Years before Peroni had been an inspector himself. As arrogant as Vieri. Maybe more so. Maybe with better reasons. He was good at that job, a leader, a man who let people run with their own imagination at times, and always or usually managed to reel them in before they went too far. Then his job and his private life collided and when he woke up from that crash everything he held dear was gone: family, career, a good few friends. He was lucky to keep any kind of position in the police after that, even one as a lowly agente, maybe the oldest, lowliest officer there was by now. Lucky too that, for some reason he could never understand, love came back into his life in the shape of Teresa Lupo, the morgue boss now in Venice. And friendship in the form of Costa and Falcone.

But they weren't here. He was and he could do what he d.a.m.ned well liked.

Afterwards Peroni would try to convince himself it was a considered, reasoned decision, one weighed and balanced, pros and cons, before he made up his mind. But this was, he knew, a lie, a conscious act of self-deception. The proof already lay in his pocket. On the way out he'd subtly lifted a very full notepad from the desk of one of Vieri's taciturn Milanese minions.

There was one sentence in it about Ion Dinicu and three pages about the eminent psychiatrist Giorgio Spallone and his businesswoman wife Eva. They lived in a fancy street in Parioli. It seemed a good place to start, but only after he'd checked a couple of things on the computer first.

3.

The villa was, like everything in the couple's quiet, rich, suburban cul-de-sac, daintily perfect. A three-storey detached home from the early twentieth century, soft orange stone with colourful tiled ribbon decorations over the green shuttered windows. A small orchard of low orange and lemon trees ran between the ornate iron gate and baroque front door with its stained gla.s.s and plaster curlicues and gargoyles. In the finely raked gravel drive stood a subtle grey Maserati saloon and next to it a lurid red Ferrari.

He glanced through the window of the low sports car. There were magazines on the pa.s.senger seat, t.i.tles about women's fashion, a few coa.r.s.e gossip mags and, somewhat oddly, a glossy about men's health, with a cover of a muscular bodybuilder type straining at a piece of exercise equipment. There was nothing on the seats or the dash of the Maserati. The car looked clean and tidy. And, like the Ferrari, not much used except as some icon placed behind the iron gates, one advertising the wealth of those to whom these vehicles so unsuited for the busy, narrow roads of Rome belonged.

Showy jewellery for the drive, and it wasn't hard to work out which was his and which hers.

Parioli, he thought. The place was such a byword for bourgeois sn.o.bbery that the term pariolini to describe its residents had become, for some, an insult in itself. It was a little unfair. But only a little.

He walked up to the door, rang the bell and showed his ID when a maid in a white uniform answered. She was foreign, of course. Filipino he guessed. The name "Maria" was embroidered on the uniform. She'd been crying recently and didn't look into his face after she read the ID.

"I know we've been here already. How upsetting this is, Maria," he said. "But I do need to check a couple of small details with Signora Spallone. Please ..."

She wasn't there, the maid said, still staring at the ground.

"Where is she?"

"Down at the gym."

Peroni was thinking about this when the woman sensed his puzzlement and added quickly, "It's Signora Spallone's job. She and the signore own it. She wanted to break the news to the people there. They all knew him."

"Of course," he said, nodding. "This is such a very small thing. I just need to check some clothing in their bedroom. Giorgio's. One quick look. The boss won't let me off shift until it's done. Can I ...?"

She opened the door and he walked in. The place was beautiful, spotless and palatial, walls covered in paintings, old and new, corridors dotted with what looked like imperial-era statues.

"Their bedroom?" he asked.