The Final Reckoning. Sam Bourne

The Tudor was perhaps the nearest hotel to the United Nations building. And this was the UN's big week. Heads of government from all over the world had piled into New York to address the General Assembly. US Secret Service were crawling all over the place in preparation for the President's visit later in the week, but there were more than a hundred other prize targets already here, all jammed within a few Manhattan blocks for seventy-two fraught hours. In a week like this, anything was possible. A Kurd bent on assassinating the head of the Turkish government, a Basque separatist determined to blast the Spanish prime minister, ideally on live television: you name it.

      ‘Placed a tap on the Tudor Hotel switchboard last night. Recorded a guest calling down to reception this morning, asking about visiting times to the UN. “Is it true tourists can go right into the Security Council chamber itself?”’

      ‘Accent?’ It was the first word Marcus had spoken.

      ‘Part British, part “foreign”.’

      ‘OK’

      ‘You need to get down there. Watch and follow.’

      ‘Description?’

      ‘White male. Five-eight. Heavy black coat, black woollen hat.’

      ‘Weight?’

      ‘Hard to tell. Coat's bulky.’

      ‘Back-up?’

      ‘There's a team.’

      Felipe Tavares was now outdoors. Behind him was the temporary white marquee that served as the UN visitors' lobby – still up after five years. Not much tourist traffic yet, too early. So far it was just regular UN staff, permits dangling like necklaces. Not much for him to do. He looked up at the sky, now darkening. Rain was coming.

      * * *

      Marcus stationed himself on the corner of 42nd and Second Avenue – still called Nelson and Winnie Mandela Corner – tucked into the doorway of McFadden's Bar. Diagonally opposite was the Tudor Hotel. The first drops of rain were a help; the shelter gave him an excuse to be standing there, doing nothing. And it meant the Tudor's doorman, in cape and peaked cap, was too busy fussing with umbrellas and cab doors to notice a shifty guy in dreads across the street.

      That was how Marcus liked it; to be unnoticed. It had become a speciality of his back when he was doing undercover work in the NYPD's narcotics squad. Since he had moved over to the Intel Division a year ago it had become a necessity. The thousand men and women of what amounted to New York's very own spy agency, a legacy of 9/11, kept themselves secret from everyone: the public, the bad guys, even their fellow cops.

      He had been waiting twenty-five minutes when he saw it. A blur of black emerging through the hotel's revolving door. Just as it turned towards him, the doorman stepped forward with his umbrella, blocking Marcus's view of the man's face. By the time the umbrella was out of the way, the blur of black had turned right. In the direction of the UN.

      Marcus spoke into what those around him would have believed was a Bluetooth headset for a cellphone. ‘Subject on the move.’

      Without waiting for a response he started walking, keeping a few paces behind the man on the other side of the six, traffic-filled lanes of 42nd Street. A voice crackled into his ear, sounding distant. ‘Do we have a positive ID?’

      Marcus shot another look. The man was swaddled in the thick, dark coat the handler had mentioned; his head was covered in a black woollen hat pulled low, and he was no more than five feet and eight inches tall. The subject matched perfectly the description of the man seen at the Russian's last night. He pressed the button clipped to his sleeve: ‘Affirmative. We have a positive ID.’

      Suddenly the man in black began to turn, as if checking for a tail. Of course he would: trained terrorists didn't just let themselves get followed. Marcus swivelled quickly, switching his gaze to the steps that led up to a small city playground. In his peripheral vision he could tell the subject was no longer looking at him, but was marching onwards.

      Something about the man's gait struck Marcus as odd. Was he limping slightly? There was a restriction to his movements, something slowing him down. He walked like a man carrying a heavy weight.

      Suddenly the East River came into view. They had reached the corner of First Avenue: UN Plaza was visible. The rain was getting heavier now, making it harder to see.

      The man in black had reached the crossroads, the traffic heavy. Marcus hung back on his side of the street, all the while keeping his eye fixed on the subject, who had now stopped by the first entrance to the United Nations, reading the sign: ‘Staff, Delegates and Residents. Correspondents Only.’ Now the subject moved on, separated by the black iron railings from a procession of flagpoles, each one empty. Further back loomed the trademark curve of glass and steel that was the UN headquarters.

      Marcus cursed his short leather jacket, feeble against this downpour. He pulled his collar up to stop the rain running down his neck. The man in black seemed untroubled by the weather. He moved past another UN gate, this one for cars, and another green-tinted sentry box.

      Marcus stopped for a moment in the doorway of the Chase Bank. The second he did so an oversized tourist bus – doubtless full of oversized tourists – pulled up into the slip road that fronted the UN between 45th and 46th.

      ‘Lost visual, lost visual!’ Marcus urged into his mouthpiece.

      ‘I got it,’ said another voice over the air, instant and calm. ‘Subject has halted outside main gate.’

      Marcus walked on, trying to get ahead of the tourist bus without revealing himself. His headset crackled again.

      ‘Subject back on the move.’ OK, thought Marcus with relief. A false alarm. The man in black was not trying to enter the UN building after all.

      At last the bus pulled out, giving Marcus a clear view of the subject, now walking further down First Avenue. His pace was quickening slightly, thanks to the steep downward slope. But this was no relaxed stroll. Marcus could see him studying the garden on the other side of the railings intently. He had drawn level with a large, heroic sculpture – the slaying of a dragon, the beast apparently fashioned out of an old artillery cannon – and stopped as if looking for something.

      Marcus squinted. Was he searching for another, unguarded, way into the UN compound? If he was, he clearly had not found it. Now, with renewed purpose, the man turned around, heading back towards the main entrance.

      Felipe Tavares' radio was bulky, low-tech and in this rain barely audible. It was hard to separate the static crackle from the rest of the noise. But the word ‘Alert’ came through clear enough, especially when repeated twice.

      ‘Watch Commander to main entry points, this is the Watch Commander to main entry points.’ Felipe recognized the accent: the guy from the Ivory Coast who'd started three months ago. ‘We have information on a possible threat to the building. Suspect is male, five foot eight, wearing a heavy black coat and dark woollen hat. No more details at present, but stay vigilant. Please stop and apprehend anyone fitting that description.’

      Felipe had barely digested the message when he saw a blur of black striding, head down, towards the gate he was guarding.

      Marcus was now halfway across First Avenue, struggling to hear the voice in his ear above the traffic.

      ‘… enter the UN compound. Repeat, agents are not to enter the UN compound.’

      He stopped as he reached the kerb of the slip road, now just yards away from the man he had followed for more than ten minutes, and watched him walk briskly through the gate and up the few steps to the small piazza in front of the white marquee. He had crossed into UN territory: he was now officially beyond reach. All Marcus could see was the man's back. He felt his heart fill with dread.

      From this angle, at the side of the piazza, Felipe could only see a little of the man's face in profile, the hat and the collar of his coat obscuring even that. But he fitted the Watch Commander's description perfectly.

      Felipe watched him stop, as if contemplating