'Does he know why you picked him?'

'No. That's best kept secret,' said Don Pedro, 'which will allow us to remain at arm's length for the whole exercise.'

'When does he arrive in Buenos Aires?'

'He'll be joining me on the ship this evening, and he will be safely back in England long before anyone works out what we were up to.'

'Do you think he's old enough to carry out such an important job?'

'The boy's older than his years and, as important, he's a bit of a risk-taker.'

'Sounds ideal. And have you put Bruno in the picture?'

'No. The less he knows, the better.'

'Agreed,' said Diego. 'Is there anything else you want me to do before you arrive?'

'Just make sure the cargo is ready for loading and is booked on to the Queen Mary for its return journey.'

'And the bank notes?'

Don Pedro's thoughts were interrupted by a gentle knock on the door. He turned to see Sebastian entering the room.

'I hope I'm not interrupting you, sir.'

'No, no,' said Don Pedro, replacing the receiver and smiling at the young man who had become the last piece in the jigsaw.

Giles thought about stopping at the nearest phone box so he could ring Harry and let him know that he'd tracked Sebastian down and was on the way to collect him, but he wanted to see the boy face to face before he made that call.

The Park Lane traffic was bumper to bumper, and the cabbie showed no interest in slipping into gaps, let alone running amber lights. He took a deep breath. What difference would a few minutes make, he thought as they circled Hyde Park Corner.

The taxi finally drew up outside No. 44 Eaton Square, and Giles paid the exact sum on the meter before walking up the steps and knocking on the door. A giant of a man answered, and smiled at Giles almost as if he'd been expecting him.

'May I help you, sir?'

'I'm looking for my nephew, Sebastian Clifton, who I understand is staying here with his friend Bruno Martinez.'

'He was staying here, sir,' said the butler politely. 'But they left for London Airport about twenty minutes ago.'

'Do you know which flight they're on?' he asked.

'I have no idea, Sir Giles.'

'Or where they're going?'

'I didn't ask.'

'Thank you,' said Giles, who after years as an opening batsman recognized stonewalling when he faced it. He turned to look for another taxi as the door closed behind him. He spotted an illuminated yellow sign and hailed the cab, which immediately performed a U-turn to pick him up.

'London Airport,' he said, before climbing quickly into the back. 'And I'll give you double what's on the clock if you get me there in forty minutes.' They pulled away just as the door of No. 44 opened and a young man came running down the steps, waving at him frantically.

'Stop!' Giles shouted. The taxi screeched to a halt.

'Make your mind up, guv.'

Giles pulled down the window as the young man ran towards him.

'My name is Bruno Martinez,' he said. 'They haven't gone to the airport. They're on their way to Southampton to join the SS South America.'

'What's her departure time?' asked Giles

'They're sailing on the last tide around nine o'clock this evening.'

'Thank you,' said Giles. 'I'll let Sebastian know - '

'No, please don't, sir,' said Bruno. 'And whatever you do, don't tell my father I've spoken to you.'

Neither of them noticed that someone was staring out of the window of No. 44.

Sebastian enjoyed sitting in the back of a Rolls-Royce, but was surprised when they came to a halt in Battersea.

'Ever flown in a helicopter before?' asked Don Pedro.

'No, sir. I've never been on a plane before.'

'It will take two hours off our journey. If you're going to work for me, you'll quickly learn that time is money.'

The helicopter soared into the sky, banked to the right and headed south towards Southampton. Sebastian looked down on the early evening traffic as it continued its snail-like pace out of London.

'I can't do Southampton in forty minutes, guv,' said the cabbie.

'Fair enough,' said Giles, 'but if you can get me to the dockside before the SS South America sails, I'll still double your fare.'

The taxi driver shot off like a thoroughbred out of the stalls, and did his best to overcome the rush-hour traffic, taking back doubles, going down side streets Giles hadn't realized existed, moving across into the oncoming lane before swerving back to run lights that had already turned red. But it still took over an hour before he emerged on to Winchester Road, only to find that long stretches of roadworks restricted them to a single lane and the speed of its slowest driver. Giles looked out of the window and didn't see that much road work in progress.

He kept checking his watch, but the second hand was the only thing that kept a steady pace, and the chances of them making it to the docks before nine were looking more and more unlikely by the minute. He prayed that the ship would be held up for just a few minutes, although he knew the captain couldn't afford to miss the tide.

Giles sat back and thought about Bruno's words. Whatever you do, don't tell my father I've spoken to you. Sebastian couldn't have asked more of a friend. He looked at his watch again: 7.30 p.m. How could the butler have made such a simple mistake when he said they were on their way to London Airport? 7.45 p.m. It clearly wasn't a mistake, because the man had addressed him as 'Sir Giles', although he had no way of knowing that he was about to turn up on his doorstep. Unless . . . 8 p.m. And when he said 'they left for London Airport', who was the other person he was referring to? Bruno's father? 8.15 p.m. Giles hadn't been able to come up with a satisfactory answer to any of these questions by the time the taxi swung off the Winchester Road and headed for the docks. 8.30 p.m. Giles set aside all his misgivings and began to think about what needed to be done if they arrived at the dockside before the ship had raised its anchor. 8.45 p.m.

'Faster!' he demanded, although he suspected the driver already had his foot flat to the floor. At last he spotted the great liner, and as it grew larger and larger by the minute, he began to believe that they just might make it. But then he heard a sound he had been dreading: three loud, prolonged blasts of a fog horn.

'Time and tide wait for no man,' said the driver. An observation Giles could have lived without at that particular moment.

The taxi came to a halt by the side of the South America, but the passenger ramp had already been raised and the mooring ropes released to allow the vast ship to ease its way slowly away from the dockside and out into the open sea.

Giles felt helpless as he watched two tugs guide the ship out into the estuary, like ants leading an elephant to safer ground.

'The harbourmaster's office!' he shouted, without any idea where that might be. The driver had to stop twice to ask for directions before he pulled up outside the only office building that still had all its lights on.

Giles jumped out of the taxi and charged into the harbourmaster's office without knocking. Inside, he came face to face with three startled men.

'Who are you?' demanded a man dressed in a port authority uniform, displaying more gold braid than his fellow officers.