'Back so soon, Dr Vitali? Did you forget something?'

'Well, yes,' replied Sonia. 'I left a book of notes downstairs, and since I had to come back for them, I thought there were still a few things I could usefully do.'

She moved swiftly downstairs to the storeroom with Mario, who inserted a key in the door for her. As Sonia slipped in, she said, 'Please go on home, Mario. When I've finished I'll set the alarm and pull the main door shut behind me.'

She closed the door before Mario could answer. He slowly climbed the stairs up to the ground floor. He was used to the strange habits of academics and researchers: people who lived in another world, just like Balestra, the director, who closed himself up in his office for weeks on end, studying Lord knows what. He hung the keys on a hook in the security guard's booth, put on his coat and walked outside. There were just a few steps between the museum entrance and the front door to his house, but he felt as weighed down as if he were wearing shoes of lead. A strange feeling he'd never experienced before.

Meanwhile, in the basement, Sonia switched on the overhead light as well as the spotlight that was trained on the big skeleton standing on a wooden platform at the end of the room. She had wired the bones together using a system of steel bindings she had devised herself. For the first time, she saw it with new eyes: no longer as a palaeozoological specimen but as a fleshless monster, a Cerberus straight out of hell.

She drew in a long breath and approached the pedestal. She had collected all the leftover bone fragments on a piece of white felt. She knelt down and began to pick out the pieces that surely belonged to the human skeleton: fragments of the skull a several of which still bore the marks of the fangs that had crushed it a and of the long bones, the humeri and femurs cruelly snapped by the bite of powerful jaws. She then began to examine the remaining fragments: ribs, vertebrae, phalanxes, astragali . . .

She sighed. What criteria could she use in separating them? There were certainly a number of options, all of them reliable, but given the conditions and the urgency a what emergency could Fabrizio possibly be on about? a there was just one fast, sure way: colour. The animal bones were a bit darker.

'I guess I'll just have to make do with what I have,' she mused aloud.

She took some of the plastic boxes they used for collecting archaeological finds and stacked them up next to the bone fragments on the white felt. She took a Polaroid camera from her bag, climbed up her improvised staircase and snapped one, two, three shots at slightly different angles. She examined the prints one by one, chose the best and then ran up to the first floor. There was no one in any of the offices. She reached the laboratory and switched on the highest-resolution scanner. She framed a single fragment and took that colour tone setting, then programmed the machine to recognize all objects having the same tone and to highlight them. In just a few minutes the printer provided an image with all the selected fragments. Sonia shut off the machine and the lights and ran back underground, carefully bolting the main door as Fabrizio had ordered. Then she placed the printout on the ground and began to sort out each one of the highlighted fragments, laying them carefully on the wooden pedestal beneath the skeleton.

FRANCESCA grasped Angelo's hand without taking her eyes off the opening to the tunnel, which was framed by the beam of torchlight.

'We're here. Come on, little guy. Let's give it a go.'

They started to advance, very slowly, clinging to each other, preparing to meet the beast's charge. And all at once the sound of powerful legs, the scraping of sharp claws on stone, got closer and closer until they were face to face. Huge, dreadful, mouth foaming, eyes shot through with blood, monstrous fangs bared to the root. The child screamed and Francesca shouted out loud to release a burst of unbearable tension. The animal responded with a furious roar. Angelo and Francesca cowered against the wall, overwhelmed by horror. The snarling beast drew closer, a deep rattle coming from its throat, and Francesca understood that what she'd done was insane. She shielded the boy with her own body, hoping that the monster would be sated by her blood alone.

SONIA heard the doorbell ringing insistently and then a furious banging of fists on the door. The main entrance! She'd forgotten the bolt on the door upstairs! She left the room, ran up the steps and towards the door, yelling as she went, 'Who's there?'

'It's me, Fabrizio! Open the door, fast. Now, Sonia! We only have a matter of seconds. Open up!'

Sonia slid the bolt and found Fabrizio soaked with sweat and brandishing a heavy gas canister connected to a blowtorch. His car was blocking the deserted street, its headlights on and door wide open.

'What in heaven's name . . .' she blurted out.

But Fabrizio was already dashing along the corridor and down the stairs, shouting, 'Get over here! Did you finish what I asked you to do? Have you separated all the fragments?'

Sonia ran after him breathlessly without even closing the door, shouting back, 'Yeah. I think so, at least, but what is that thing you've got in your hand? What the hell are you going to do with it? Burn down the place? Talk to me, goddamn you, Fabrizio! I swear I'll sound the alarm unless you stop right now. I swear I'll do it! Stop and listen to me!'

But Fabrizio seemed possessed. He ran carrying the heavy iron canister as if it were made of paper. He reached the skeleton, recognized the human bone fragments lying on the felt, then turned back to the skeleton and the animal bones that Sonia had piled up on the wooden pedestal. He opened the gas valve, pulled a lighter out of his pocket and applied it to the burner. A blue flame burst from the torch and Fabrizio moved towards the skeleton.

'No!' shouted Sonia. 'No! What are you doing? Damn you! You can't do that! Don't destroy it! Stop!'

She jumped at him to make him stop, sure that he'd gone mad, that he'd lost his mind. But he spun around and hit her hard in the face, knocking her to the ground. He directed the blowtorch at the skeleton, which started to burn. The metal bindings became incandescent and twisted in the flames, the structure collapsed and the skeleton of the beast, so patiently and laboriously reassambled, disintegrated one bone at a time, crumbling on to the wooden base, which burst into flame all at once. The fire grew in intensity as the great skeleton turned to ash.

AT THAT same instant, in the underground tunnel, just as the beast was about to spring, it was enveloped in a whirlwind of flames. Francesca watched incredulously as it reared up on its hind legs, writhing in the grip of powerful convulsions. It let out a terrifying roar, a cruel and desperate howl of pain that almost seemed human. The girl turned and hugged the child tight, flattening herself against the wall, frantically covering his eyes and his ears to spare him the sight of such horror and the sound of such unending suffering. The entire tunnel trembled, as if shaken by a violent earthquake, as the walls echoed the cries of the dying beast. The howl disintegrated into a shriek of pain and Francesca's ears filled with moaning and sobbing, suffocated words in a forgotten language, prayers and imprecations welling up from the abyss of millennia. Then everything was plunged into a silence deeper than death.

FABRIZIO extinguished the flame and mopped the sweat from his forehead. He was completely drenched from head to toe, as if he had accomplished the most strenuous task of all times.

He turned immediately to Sonia and blurted out, 'I'm so sorry. I didn't mean . . .' But she was gone.

He turned off the gas valve, ran back upstairs through a thick curtain of smoke and rushed out into the street, where he was nearly run over by Reggiani's police van.

'Your colleague Sonia Vitali just called me. What the hell do you think you're doing? Get into the car now. I'm going to keep you under lock and key until all this is over.'

Two soldiers flanked him while Reggiani turned to his radio and instructed, 'Open fire as soon as it comes out.' He turned back to Fabrizio then and said, 'There's no chance of it getting away. The moment it surfaces, it'll be blinded by half a dozen two-thousand-watt photoelectric cells and riddled with shots.'

'No!' shouted Fabrizio. 'You don't understand! Francesca and Angelo are down there and they might be trying to get out. You risk killing them instead of the animal. They're still underground, I'm telling you! Listen to what I'm saying a I heard it howling, just moments ago, but it was different this time. It was horrible. I'd never heard anything like it before. Come on, Marcello, for the love of God! Order your men to hold their fire, please! I'm begging you!' He was weeping openly.

'All right!' growled Reggiani. 'But let's get moving, damn it!'

Fabrizio took off at a run towards the Caretti-Riccardi palace with Reggiani close behind and the police van following. Sonia, her eyes full of tears and her face swollen, emerged from a dark corner and went back to the museum entrance, but she didn't even have the strength to go up the stairs. She collapsed on to the step at the threshold and, with a long sigh, leaned her head back against the door.

Fabrizio burst into the square and ran towards the main entrance to the palace. He pushed at the side door at the centre of the facade and it yawned open without any resistance. He dashed in while Reggiani quickly grabbed the van's radio.

'Do not open fire unless you are absolutely certain you have the animal in your sights. There are people underground who may be trying to escape through the cistern. I repeat, people are present.'

'Roger that, sir,' replied Tornese's voice. 'We'll be careful.'

Reggiani replaced the transmitter and took off after Fabrizio, followed by a couple of his men. They ran breathlessly to the end of the great hall, which rang out with the pounding of their combat boots. They tramped down the stairs and through the cellar, trying to keep up with Fabrizio, who was racing along as if he could see in the dark. He finally entered the tunnel without ever pausing for breath and ran until he found Francesca, who was sobbing disconsolately. She had collapsed to the ground and was holding the child tenderly in her arms. The animal was nothing more than a dark, shapeless, burnt mass on the tufa floor.

'It's all over,' said the girl between her sobs.

Fabrizio had pulled up short, paralysed by what he was seeing. He whispered, 'Only if the beast is separated from the man . . .'

'Only if the child is returned to the father . . .' continued Francesca, and she opened her arms. 'He's dead. Angelo is dead. His father took him away with him.'

Reggiani shouted to his men, 'Call an ambulance! A doctor, fast!'

Fabrizio lifted the child and laid him gently on the ground. He began a cardiac massage and tried blowing air into his lungs. He could feel heat and got a whiff of his little boy's smell: life couldn't have completely abandoned him yet. Francesca was leaning against the wall and crying hot tears in silence. Reggiani was frozen in place, his loaded pistol still in hand, a wordless witness to the scene.

All at once Fabrizio distinctly felt a draught of cold air coming from the side tunnel and he seemed to be struck by a sudden awareness. He got to his feet, still holding the little boy to his chest, and began to advance down the dark passageway.

Reggiani started. 'Where are you going?' he said. 'Wait!'

He moved off after them, still holding his pistol in his right hand and a torch in his left. They continued for ten or twelve metres, until the tunnel walls squared off suddenly and came to an end at a carved doorway.

'My God!' murmured the officer, astonished at the sight. 'What is that?'

Fabrizio had already entered and Reggiani could see a beautiful fresco beyond him, on the opposite wall, depicting a banquet scene with dancers and flute players draped in light, transparent gowns.

'It's their tomb,' replied Fabrizio with a tremble in his voice. 'It's the Kaiknas family tomb.'

Fabrizio turned and saw a large sarcophagus bearing the image of a husband and wife, reclining on their sides: the lady was beautiful and her spouse had the powerful build of a warrior. His arm was wrapped around her shoulder in a gesture of love and protection. Reggiani directed the torch beam on them and remained speechless in contemplation of their timeless faces and enigmatic smiles.

Fabrizio fell to his knees in front of the sarcophagus, stretching the still body of the little boy forward towards them. 'Let me keep him!' he pleaded. 'Let him live! He can't die twice! I beg of you, leave him to me!' He burst into tears and clasped the little boy's body close to his chest.

The dark underground chamber was once again invaded by that cold, mysterious, sudden breath of air, and Fabrizio heard a sound that roused him from his weeping: a whisper more than a sound; a long, sorrowful sigh.

'Did you hear that?' he asked Reggiani.

The officer shook his head, regarding Fabrizio with a pitying expression.

'Francesca . . .'

'Who said that?' asked Fabrizio in surprise, but as he spoke he felt a shudder run through the little body he was clutching and then he felt the rhythm a hiccuping at first and then slow and even a of the child's breathing.

'Shine that over here!' he shouted frantically, and Reggiani illuminated the face of the little boy, who blinked in the sudden harsh light. The two men stared at each other without managing to get a word out.

'Where's Francesca?' repeated Angelo. 'What is this place?'

'Francesca? We'll find her. She's right here, close by,' replied Fabrizio, trying to control his emotions and speak as normally as possible.

They walked back towards the main tunnel, while the mausoleum of the Kaiknas family sank into darkness and silence again.

They joined Francesca and tried to retrace their steps, but the tunnel was obstructed by a landslide, as if there had been an earthquake.

'All we can do is go on towards the cistern,' said Francesca. 'We have no choice. I hope your men aren't feeling trigger-happy,' she added to Reggiani.

They walked for about twenty minutes in the dim glow cast by the torch. When they were approaching the cistern, Reggiani called out, 'It's us! We're coming out!'

'We're waiting for you, Lieutenant! It's safe to come out,' came back the sergeant's voice, followed by a thump and a loud buzz as the photocells flooded the cistern well. The four people who had been feared buried alive came out one after another, last of all Fabrizio with the child on his shoulders.

An ambulance soon pulled up and a couple of nurses came out with a stretcher, accompanied by a doctor.

'He's fine now,' said Fabrizio. 'He fainted, but he's better now.'

'I'd still like to have a look,' said the doctor, who had been given a much more alarming prognosis by Reggiani's men. 'I think it's best we keep him under observation for the rest of the night.'

Francesca took Angelo's hand. 'I'll go with him. Don't worry. We'll see you in the morning.'

Fabrizio kissed her and held her tight. 'You were very brave. I never would have forgiven myself if anything had happened to you . . . I love you.'

'I love you too,' replied the girl, leaving him with a gentle caress.

Lieutenant Reggiani mustered his men. 'The operation is suspended,' he announced. 'The animal has been destroyed.'

'Destroyed?' repeated Sergeant Massaro. 'How?'

'With . . . a flame-thrower,' replied Reggiani curtly.

'A flame-thrower, sir?' asked the sergeant incredulously.

'That's correct. Why? Is there something strange about that?'

'No, nothing. I was just thinking . . .'

'No need to rack your brains, Massaro. Everything's fine, I can assure you of that. You can demobilize now and return to headquarters. It's all over. There will be no more deaths. All I have to do now is face the Home Secretary and the press, but at least they don't bite . . . At least, I hope not.' He turned towards Fabrizio. 'Where can I drop you off?'

'At the museum. My car is still in the middle of the road and . . . there's something I still have to do.' He switched on his mobile phone and called Sonia, but her phone was off and when they reached the museum there was no trace of her.

'I'll call her tomorrow,' he said. 'I have to ask her to forgive me. Or . . . would you like to call instead?' he asked Reggiani, guessing at his thoughts. 'Yeah, I think that's a better solution. Here, this is her number. Tell her that I'll call her as soon as I can and that I'm very, very sorry, but that I had no choice. You know why.'

'I'll take care of it,' promised Reggiani. 'What's next?'

'Come in. There's something I want to show you.' He took the key from his pocket, opened the door, crossed the hall and walked down the stairs to the basement. The room was still full of smoke and invaded by an intense, acrid, scorched smell.

Reggiani noticed the gas canister and burner. 'You could have blown up the whole place. You're completely irresponsible.'

'I told you I needed a flame-thrower and this was all I could find. Thank God I did! I remembered seeing a roadworker using something like this once to melt tar.'

'I think you owe me an explanation,' said Reggiani. 'Even if this is all over, I want to know what set the whole thing off and how.'

Fabrizio took a folded sheet of paper out of the inside pocket of his jacket and handed it to Reggiani. It was the translation of the inscription. 'Read this. You'll understand everything. It's the text of the slab of Volterra. Complete.'

As the lieutenant scanned the crumpled sheet in disbelief, Fabrizio bent down and carefully gathered the bones of the Phersu that Sonia had painstakingly separated from the animal's bones. He walked towards the stairs.

Reggiani turned towards him, still shaking his head. 'Where are you going now? Haven't you got into enough trouble for one night?'

'I'm going back down there,' he said without turning. 'I'm going to take Turm Kaiknas's bones to the family tomb, so he can rest alongside his wife and his child. I'm certain about one thing at least. The statue of the young lad in room twenty above our heads, the one I came to study, comes from that tomb. Have all the entrances to the tunnel closed tomorrow in secret if you can. No one must ever disturb the sleep of Turm and Anait again, for any reason.'

Back up in the front hall, Fabrizio turned out the lights and set the alarm before leaving. 'In a few days we'll be asking ourselves if we dreamed it all. You know we're going to forget this, don't you? That's what happens to the human mind when events are too difficult to accept. Anyway, I think we've done the right thing. And what counts is that your case is solved, isn't it, Lieutenant?'

'No, not completely,' objected Reggiani as they walked towards the car. 'We still don't know where Angelo comes from.'

'Maybe Ambra Reiter will tell you the next time you question her.'

'You think so? I'm sure she'll come up with the most obvious story possible. That when her first husband died he made her promise to bring the child to safety in Italy. She may even have an ID card, documents.'

'Maybe . . .' said Fabrizio as if talking to himself. 'But the wounds of the past can come back to bleed again in the present. Sometimes they can even hurt. Debts have to be settled, sooner or later. The truth a if it exists a is buried deep in the mind of that little boy, lurking in his dreams, waiting for the shades of twilight to come calling.'

TWO DAYS LATER , Lieutenant Reggiani was back in his office at seven a.m. His expression gave no hint of the hellish events of the past fortnight. Instead, his face wore the perplexed expression that he got when he was trying to work his way through a complicated problem. He sat at his desk and began to sketch out a diagram with all the individuals who had played a role in the case and the relationships between them. After a couple of good nights' sleep, his mind was functioning again as usual and was refusing to accept an explanation that had nothing rational about it. As time passed and he got over the shock of what he'd seen down in that tunnel, he wondered whether the case was solved after all. Might there not be another murder that very night, or in two or ten days' time? In the end, all he had seen in the tunnel was a black mass on the ground that could have been anything. And a woman and child crying. He was startled from his thoughts by a knock at the door.

'Come in!' he called out, without looking up from his chart.

Sergeant Massaro stepped in and saluted him respectfully. 'Good morning, sir.'

'Good morning to you, Massaro. News?'

'Big news, sir.'

'What's that?'

'We've been following Reiter, as you instructed, and we've received the information we requested from the database at headquarters and from Trieste as well, where she was first picked up for questioning. I think we've got this solved, sir.'

'If that's the case, Massaro,' replied Reggiani, 'I'm recommending you for a promotion. Let's hear.'

'The child, Angelo that is, may have a first and last name: Eugenio Carani. That's the name of the child who disappeared from a household where Ambra Reiter had been employed as a housekeeper. When the child's parents reported him missing, she was tracked down near Colloredo and arrested, but there was no trace of the child. She was interrogated at length but nothing came of it. She denied knowing anything about the boy's whereabouts. What did become evident was that she was suffering from mental illness. She was diagnosed as borderline, with a dissociative disorder. Suspected schizophrenia, even. Her medical record is very complex.'

'And the family she was working for never noticed anything?'

'Apparently not. They said she was moody, but nothing out of the ordinary.'