'It's an "I don't give a fuck".'

'Karen, it's important. Someone has killed six people, starting with Laura. We need to stop him.'

'I need money.'

McEvoy pulled his wallet from his pocket. 'I only have ten euro,' he lied, taking the note and offering it to her.

She clutched it in her hand and looked at him, suspicious at how quickly and easily he'd given it to her.

'Did she have a boyfriend, Karen?'

'I don't know.'

'Well, did you ever see her with a man? Perhaps someone older than her?'

She hesitated, taking a drag from the cigarette. 'No.'

'Are you sure? He kills people, Karen. He killed Laura.'

'I said, no, didn't I. She kept herself to herself. Herself and her dog.'

'What happened to the dog?'

'Look, I've got to go,' she turned and started to walk away towards Earl Street.

McEvoy trailed after her. 'Karen? What happened to the dog?'

'I don't know. I barely knew her, okay?'

'Did she have a boyfriend, Karen?'

'Will you leave me alone! This is harassment.'

People were staring at them now. Several had recognised him from the TV and newspapers. He stopped trailing her and headed back toward the GPO. He spoke into his radio mic. 'I need someone to follow that girl and keep her under surveillance.'

'I'm on it,' Cronin replied into his earpiece.

'Shit!' McEvoy snapped annoyed with how the encounter had gone, that he'd been identified. He passed Deegan who glared at him, his lips curled in an amused smile.

'Superintendent McEvoy? It's Kathy Jacobs.'

'Oh, hi. How're things going?' He rubbed his freshly shaved face and looked at his watch 4.54.

'Slowly. I've been through most of the material and my opinion hasn't changed. I still think this is about ego and I still think Laura Schmidt knew her killer.'

'I spoke to one of her friends earlier,' McEvoy said. 'I asked her if Laura had a boyfriend. She said no, but I don't believe her. She knows more than she's saying.'

'Can I talk to her?'

'After all this has finished. I have her under surveillance right now. I couldn't leave my post here.'

'Well, actually, that's partially why I'm ringing. I was won-dering whether I could join you?'

'What for?'

'Because I'm tired of these files and I want a change of scene. I thought I might be able to help.'

McEvoy paused, pondering her request. What harm could it do, he reasoned, maybe she would spot something the others wouldn't. 'Sure, come along. Just make sure you're not followed and ring me when you get here.'

'Thanks. I'll see you soon.'

McEvoy placed the mobile phone in his pocket and walked to the window facing out over O'Connell Street. It was still busy with shoppers despite the road blockage. He was feeling sick with nerves, restless and agitated, and the involuntary shake had returned to his left hand. The best part of three quarters of the day had passed and there had been no sign of The Raven or another murder elsewhere in the city. Everyone was tired and bored, the teams on the street cold and weary. At least it hadn't rained yet, despite Met eireann's forecast.

The Raven sat near to the window in McDonalds. He scratched at his back, uncomfortable with the fit of the bra. He opened the burger carton with leather-gloved hands and looked at the sad looking roll it contained, strips of lettuce poking out. Making sure no one was watching he reached into his handbag and extracted another burger in a clear plastic bag, a bite mark shape missing. He flipped open the bun, extracted the burger, and replaced it with his own. He then ripped away a chunk of bread to match the bite mark. He slid a business card and the final chapter, wrapped in clear plastic, under a serviette, placed them beneath the bun, and closed the lid.

He ate a few fries, placed the Styrofoam carton in his handbag, and shuffled to the trash disposal, tipping in the fries and redundant burger. He left the fast food restaurant, catching his reflection in the glass in the door. Grey hair tufted out of the scarf covering his head, a black coat covered a patterned blue dress and navy cardigan. He reminded himself of his grandmother. He pulled a rye smile and stepped out onto O'Connell Street, his heart beating fast, nerves tingling with anticipation.

Crossing the road, free of traffic, to the central reservation and the sculpture of the running hare, he sat down on the plinth next to a homeless man with a wispy beard, dressed in a shabby tweed jacket, filthy jeans and battered black boots. A dirty red rucksack rested between his legs, a can of Special Brew balanced on his thigh. Taking the burger carton from the handbag he offered it to him.

'I saw you from the window.' He gestured at McDonalds. 'You look hungry. Do you want it?' He held the carton to the man.

He looked at her suspiciously an interfering auld wan.

The Raven smiled and pushed the carton closer to him. 'It's just a burger.'

The man reached out and grabbed the carton. He opened it and stared at the bun, a single bite taken out of it, and then at the elderly woman. After a pause he fished it out and took a tentative bite, chewing for a second or two before taking another one, cramming it into his mouth.

The woman smiled, tapped his arm, stood up and headed away from the spire toward Parnell Square. After a few yards she glanced back. The homeless man was still in place, the carton and can now on the floor, the lager spilling across the pavement.

The homeless man convulsed and toppled off the plinth onto the pavement, his head smacking heavily on the concrete. A woman nearby startled and moved towards him, putting down her shopping bags, and kneeling down next to his head. His face was bright red, bread and burger spilling from his mouth into his beard. She looked up at two teenagers sitting on the plinth and at passers-by, unsure what to do. A middle-aged couple joined her, the man kneeling beside her, trying to loosen the clothing round the man's neck.

'Sir,' Dr John stated, zooming the camera in on the incident.

'What's happening?' McEvoy asked concerned.

'I don't know.'

'Person down at twelve o'clock,' McEvoy barked into the radio. 'Nearest to it investigate, everyone else stay in position. I'm going down there,' he said to the rest of the room. He headed to the door, followed by Kathy Jacobs. 'Get an am-bulance.'

They descended the stairs, exited out onto O'Connell Street and half-walked, half-ran, toward the crowd that had gathered near to the running hare. He looked at his watch just gone six o'clock. The sound of a siren approached from the Rotunda.

McEvoy pushed his way through the crowd. A homeless man was lying on the ground, a red rucksack between his legs. A uniformed guard was down on both knees checking for a pulse. The guard looked up and shook his head, signalling that the man was dead.

To one side the three people who had tried to help looked on, their faces creased in concern. Charlie Deegan hovered nearby.

'Right, okay,' McEvoy said, taking charge. 'Come on, move back please, give us some space here. Come on! Charlie, give us a hand, we need to secure this area. Please, ladies and gentlemen, move back.' He moved forward with his arms spread, forcing the onlookers backwards.

A couple of people in the crowd had recognised him, hurrying away, afraid they might be next, others took out mobile phones and started to film or take photos.

McEvoy realised it had been a mistake to come down before they knew that The Raven had struck. The man might have died of natural causes, in which case the operation was compromised. He cursed himself.

'Sir!' the uniformed guard called out as an ambulance pulled to a stop.

McEvoy glanced back and the guard motioned him over. The guard pointed down to the open carton at the man's feet. The burger had spilled out onto the pavement, the serviette stuck to the bun. Inside the carton the plastic-sealed note and card were visible.

'Fuck!' McEvoy spat, his guts knotting and liquefying at the same time. The Raven had struck right under their noses and nobody had noticed a thing.

'Sorry mate, can you get out of the way?' a paramedic asked.

'Don't give him CPR,' McEvoy instructed, stepping backwards. 'He's likely to have been poisoned.' He pointed to the carton.

'You sure?' the man asked.

'Ninety-nine percent.' He spoke into his radio mic. 'Right, okay, he's struck. We need this whole area cleared as soon as possible. I want the whole street locked down. Anyone within 100 metres of the spire, shepherd them down towards the Liffey for questioning. No one's to leave before they've given a full statement. Roll back the video and see if you can see what happened. Michael, you better get down here.' He turned away and swore again.

'Come on, come on, get these people back from here,' he yelled at his colleagues. 'Quickly.' He joined them, herding the on-lookers back toward the spire. The killing had taken place right at the edge of their surveillance box, probably the limit of the latitude and longitude they'd been given.

Charlie Deegan had edged closer.

'You've really fucked up this time, McEvoy,' he gloated.

'Just do your job, Charlie.'

'At least I'll have a job. You're finished. Gone.'

'I said, just do your job,' McEvoy repeated.

'You're history, McEvoy. Yesterday's man. The AC is going to chew you up and spit you out. And the press will do the same.'

Something snapped inside. McEvoy's right fist landed on Deegan's cheek. He yanked it back and launched it forward onto his nose. Deegan collapsed to the pavement, blood starting to trickle from a nostril.

McEvoy stared down at him, the red mist still clouding his vision. 'Get out of my sight, Charlie, and stay out of it. You come back and I won't be accountable for my actions. You hear?'

Kathy Jacobs was tugging on his sleeve, pulling him back.

'Leave. Now,' McEvoy commanded.

Deegan gathered himself and stood unsteadily. 'You've just made a big mistake, McEvoy. Assaulting a fellow officer. And I've got witnesses.'

'Just leave before you regret staying.' McEvoy tugged his arm free of Jacobs' grasp and lurched towards Deegan, who stumbled backwards, fear in his eyes.

'You're finished, McEvoy.'

'Play that back again,' McEvoy instructed.

At the very top of their screen they watched what looked like an elderly lady cross to the central reservation and sit down next to the victim. She opened her handbag and offered something to the man. After a hesitation he took it, opened it and removed the burger, taking a bite and then another. The old woman stood up and walked back across to the pavement and out of view.

'Is there any way of zooming in on her?' McEvoy said, frustrated. 'It's impossible to see what she looks like.'

'Not here. I don't think we have the kit,' Dr John stated. 'We'd need the techies to fiddle with it.'

'Shit!' The incident had happened 40 metres from the camera and the figures were indistinct and grainy. 'How long ago was that taken?'

'About 20 minutes. She left eight minutes before he had his fit.'

'Get her, I mean his, description sent out to all units. He'll be well beyond the outer cordon by now. We need to see if we can track his route in and out of the city centre. Also get the tape from McDonald's. It was a McDonald's carton and it's just across the road from where the body was found. Maybe they have some better quality images.'

'I'll get on it now.'

'We've fucked up big time,' McEvoy said to no one in particular. 'He killed that man right under our noses and we didn't even notice. He could have sat there for another half an hour or more before we'd have picked up on it.'

Foster had placed the business card in a clear plastic bag. McEvoy studied it, reading the text aloud. '"The Rule Book. A self-help guide for would-be serial killers. Now published and serialised in all good newspapers." For feck's sake! How about the chapter?'

Foster handed him the sheet of paper wrapped in a second plastic bag. McEvoy read it silently, Jacobs at his shoulder.

The Rules

Chapter Seven O: The Murderer D.

"At the same time that we are moving into a surveillance society, our lives more and more captured by video cameras and in databases, criminals are becoming ever more adept at avoiding their gaze. They can walk down a busy street and just fade anonymously into the background, all the while seeking a new victim."

7a. Live an ordinary life. Go to work, have a partner, make friends, mow the lawn on Sunday. Act like everyone else. Do not draw attention to yourself.

7b. Do not drink or smoke it impairs judgement and makes one edgy.

7c. Always wear a full disguise. Vary this disguise depending on context. Never wear the same disguise across victims.

7d. Always have an alibi. Make sure it is as watertight as possible, preferably recorded in some fashion.

7e. Never feel remorse or guilt they probably deserved it at some level. There is no such thing as innocence, just as there is no Truth.

7f. ALWAYS get away with it.

Master rule: Do not get caught for anything else drink driving, speeding, thieving. Have no record and no contact with the law unless necessary.

'Jesus Christ,' McEvoy hissed as he finished. 'He did it right under our feckin' noses. It's even in the bloody quote. He killed him in the middle of a busy street. He was visible to everyone, yet no one saw him. You said he'd been wearing a disguise,' he said to Jacobs.

'The trickster,' Jacobs stated flatly. 'I think the title is a pun of sorts. Chapter Seven O, Murderer D. OD. He killed him with an overdose of some kind.'

His phone rang. 'McEvoy.'

'What the hell is happening, Colm?' Bishop asked.