Dr Jamieson began to search the crowd again, the effort draining his face. A gigantic bellow from the crowd deafened him as the gold-plated royal coach hove into view behind a bobbing escort of household cavalry. He tried to see if Remmers looked around at an accomplice, but the man was motionless, hands deep in his pockets.

‘Damn you!’ Dr Jamieson snarled. ‘Where’s the other one?’ Frantically he pushed away the blind, every ounce of his shrewdness and experience expended as he carried out a dozen split-second character analyses of the people below.

‘There were two of them!’ he shouted hoarsely to himself. ‘There were two!’

Fifty yards away, the young king sat back in the golden coach, his robes a blaze of colour in the sunlight. Distracted, Dr Jamieson watched him, then realized abruptly that Remmers had moved. The man was now stepping swiftly around the edge of the crowd, darting about on his lean legs like a distraught tiger. As the crowd surged forward, he pulled a blue thermos flask from his raincoat pocket, with a quick motion unscrewed the cap. The royal coach drew abreast and Remmers transferred the thermos to his right hand, a metal plunger clearly visible in the mouth of the flask.

‘Remmers had the bomb!’ Dr Jamieson gasped, completely disconcerted. Remmers stepped back, extended his right hand low to the ground behind him like a grenadier and then began to throw the bomb forward with a carefully timed swing.

The rifle had been pointed at the man automatically and Dr Jamieson trained the sights on his chest and fired, just before the bomb left his hand. The discharge jolted Dr Jamieson off his feet, the impact tearing at his shoulder, the rifle jangling up into the venetian blind. Remmers slammed back crookedly into the cigarette kiosk, legs lolling, his face like a skull’s. The bomb had been knocked out of his hand and was spinning straight up into the air as if tossed by a juggler. It landed on the pavement a few yards away, kicked underfoot as the crowd surged sideways after the royal coach.

Then it exploded.

There was a blinding pulse of expanding air, followed by a tremendous eruption of smoke and hurtling particles. The window facing the street dropped in a single piece and shattered on the floor at Dr Jamieson’s feet, driving him back in a blast of glass and torn plastic. He fell across the chair, recovered himself as the shouts outside turned to screams, then dragged himself over to the window and stared out through the stinging air. The crowd was fanning out across the road, people running in all directions, horses rearing under their helmetless riders. Below the window twenty or thirty people lay or sat on the pavement. The royal coach, one wheel missing but otherwise intact, was being dragged away by its team of horses, guardsmen and troops encircling it. Police were swarming down the road towards the hotel, and Dr Jamieson saw someone point up to him and shout.

He looked down at the edge of the pavement, where a girl in a white dress was stretched on her back, her legs twisted strangely. The young man kneeling beside her, his jacket split down the centre of his back, had covered her face with his handkerchief, and a dark stain spread slowly across the tissue.

Voices rose in the corridor outside. He turned away from the window, the rifle still in his hand. On the floor at his feet, unfurled by the blast of the explosion, was the faded newspaper cutting. Numbly, his mouth slack, Dr Jamieson picked it up.

A sentence had been ringed: ‘…one was Anton Remmers, a professional killer believed to have been hired by the second assassin, an older man whose bullet-ridden body the police are unable to identify…’

Fists pounded on the door. A voice shouted, then kicked at the handle. Dr Jamieson dropped the cutting, and looked down at the young man kneeling over the girl, holding her dead hands.

As the door ripped back off its hinges he knew who the second unknown assassin was, the man he had returned to kill after thirty-five years. So his attempt to alter past events had been fruitless, by coming back he had merely implicated himself in the original crime, doomed since he first analysed the cyclotron freaks to return and help to kill his young bride. If he had not shot Remmers the assassin would have lobbed the bomb into the centre of the road, and June would have lived. His whole stratagem selflessly devised for the young man’s benefit, a free gift to his own younger self, had defeated itself, destroying the very person it had been intended to save.

Hoping to see her again for the last time, and warn the young man to forget her, he ran forward into the roaring police guns.

Ten miles outside Alexandria he picked up the coast road that ran across the top of the continent through Tunis and Algiers to the transatlantic tunnel at Casablanca, gunned the Jaguar up to 120 and burned along through the cool night air, letting the brine-filled slipstream cut into his six-day tan. Lolling back against the headrest as the palms flicked by, he almost missed the girl in the white raincoat waving from the steps of the hotel at El Alamein, had only three hundred yards to plunge the car to a halt below the rusting neon sign.

‘Tunis?’ the girl called out, belting the man’s raincoat around her trim waist, long black hair in a Left Bank cut over one shoulder.

‘Tunis — Casablanca — Atlantic City,’ Gregory shouted back, reaching across to the passenger door. She swung a yellow briefcase behind the seat, settling herself among the magazines and newspapers as they roared off. The headlamps picked out a United World cruiser parked under the palms in the entrance to the war cemetery, and involuntarily Gregory winced and floored the accelerator, eyes clamped to the rear mirror until the road was safely empty.

At 90 he slacked off and looked at the girl, abruptly felt a warning signal sound again. She seemed like any demibeatnik, with a long melancholy face and grey skin, but something about her rhythms, the slack facial tone and dead eyes and mouth, made him uneasy. Under a flap of the raincoat was a blue-striped gingham skirt, obviously part of a nurse’s uniform, out of character, like the rest of her strange gear. As she slid the magazines into the dashboard locker he saw the home-made bandage around the left wrist.

She noticed him watching her and flashed a too-bright smile, then made an effort at small talk.

‘Paris Vogue, Neue Frankfurter, Tel Aviv Express — you’ve really been moving.’ She pulled a pack of Del Montes from the breast pocket of the coat, fumbled unfamiliarly with a large brass lighter. ‘First Europe, then Asia, now Africa. You’ll run out of continents soon.’ Hesitating, she volunteered: ‘Carole Sturgeon. Thanks for the lift.’

Gregory nodded, watching the bandage slide around her slim wrist. He wondered which hospital she had sneaked away from. Probably Cairo General, the old-style English uniforms were still worn there. Ten to one the briefcase was packed with some careless salesman’s 289 pharmaceutical samples. ‘Can I ask where you’re going? This is the back end of nowhere.’

The girl shrugged. ‘Just following the road. Cairo, Alex, you know—’ She added: ‘I went to see the pyramids.’ She lay back, rolling slightly against his shoulder. ‘That was wonderful. They’re the oldest things on earth. Remember their boast: "Before Abraham, I was"?’

They hit a dip in the road and Gregory’s licence swung out under the steering column. The girl peered down and read it. ‘Do you mind? It’s a long ride to Tunis. "Charles Gregory, MD — " She stopped, repeating his name to herself uncertainly.